Kaplan Pathology Flashcards
1. Which of the following is the MOST likely explanation for when two days after removal of a cancerous neck lesion, there is thigh and calf cramps, tingling around the lips, low serum calcium, and high serum phosphate? A. Hyperparathyroidism B. Primary hypoparathyroidism C. Pseudohypoparathyroidism D. Renal failure E. Vitamin D deficiency
The correct answer is B. Surgically related hypoparathyroidism is the most common cause of
primary hypoparathyroidism. Exploration of the anterior neck during thyroidectomy,
parathyroidectomy, or removal of neck lesions can all compromise parathyroid gland function. Often
the problem occurs because the blood supply to the parathyroid glands is interrupted during the
surgery. The decrease in plasma parathyroid hormone leads to hypocalcemia and
hyperphosphatemia. The decreased serum calcium is caused by decreased absorption of dietary
calcium (because vitamin D activation is decreased) and decreased movement of calcium from bone
to extracellular fluid. Low serum calcium can lead to tetany and paresthesias because of
destabilization of excitable tissue membranes. Tetany is most often observed when there is a rapid
decrease in serum calcium, such as that occurring with surgical hypoparathyroidism. The increased
serum phosphate is caused by decreased renal excretion.
Hyperparathyroidism (choice A) is frequently asymptomatic; however, renal stones, polyurine,
hypertension, constipation, fatigue, and mental status changes may be seen. Serum and urine
calcium is elevated. Urine phosphate is high and a low to normal serum phosphate is generally seen.
Pseudohypoparathyroidism (choice C) is a rare genetic defect in which the target tissues are
insensitive to parathyroid hormone. Because parathyroid hormone is less effective, serum calcium
decreases and serum phosphate increases. Pseudohypoparathyroidism is also accompanied by
developmental defects, including mental retardation, short stature, and missing metatarsal or
metacarpal bones.
In renal failure (choice D), hyperphosphatemia occurs because of decreased renal excretion. This
can lead to hypocalcemia as the equilibrium between serum phosphate and serum calcium is pushed
toward hydroxyapatite. Furthermore, dietary absorption of calcium is decreased because vitamin D
activation is decreased by hyperphosphatemia, even before there is significant decrease in renal 1-
alpha-hydroxylase activity. The low serum calcium produces a compensatory increase in parathyroid
hormone with subsequent bone demineralization (renal osteodystrophy).
With vitamin D deficiency (choice E), serum calcium and phosphate are typically decreased. The
calcium is low because of decreased dietary absorption. The phosphate is low (not high) because of
decreased dietary absorption, and because the secondary increase in parathyroid hormone secretion
(caused by the hypocalcemia) increases renal excretion of phosphate.
- At what level in the skin do bullae MOST likely develop in a localized cutaneous infection
around the mouth with phage group II Staphylococcus aureus?
A. Across the basal cells
B. Below the basement membrane
C. Between the basal cells and the basement membrane
D. High in the epidermis
E. Just above the basal cells
The correct answer is D. Bullous diseases of the skin are subdivided on the basis of the level at
which the cleavage for blister formation occurs. In general, the lower in the epidermis/dermis that the
cleavage plane occurs, the more dangerous and widespread the blistering. This is because blistering
at lower levels, particularly those involving the basal cell layer, permits loss of substantial amounts of
fluid and heals slowly (often with significant scarring). Scalded-skin syndrome (toxic epidermal
necrolysis) may follow staphylococcal (often phage group II) skin infection. This disorder fortunately
involves the very superficial squamous cells just beneath the granular layer. Consequently, the
disease (which typically produces bright red skin sloughing) usually resolves without sequelae after
antibiotic therapy. “Scalded-skin” may also be observed in association with drug-induced erythema
multiforme. Major inciting agents include phenylbutazones, sulfonamides, barbiturates,
aminopenicillins, oxicam, nonsteroidal antiinflammatory agents, and allopurinol. This form usually
affects the mucosa (eyes, mouth) first, and is much more dangerous because the blistering is
subepidermal, and the entire overlying epidermis becomes necrotic.
- Which of the following cell types show abnormal function when there is a history in a young
adult of multiple arm and leg fractures following minor falls, with a slight weakness of facial
muscles on the left, mild anemia, and with generalized bony widening with partial obliteration
of marrow spaces?
A. Granulocytic stem cells
B. Megakaryocytes
C. Plasma cells
D. Osteoblasts
E. Osteoclasts
The correct answer is E. The disease described is osteopetrosis (Albers-Schonberg disease), which
is a group of hereditary diseases in which impaired osteoclast function leads to reduced bone
resorption. The abnormal osteoclasts frequently are enlarged, with bizarre shapes. The bones
become thick and brittle; other features include anemia secondary to marrow loss and cranial nerve
deficits secondary to narrowing of bony ostea. An autosomal recessive, severe form of the disease
produces death in childhood. A relatively benign, autosomal dominant form presents in adulthood.
Abnormal proliferation of granulocytic stem cells (choice A) can produce myelocytic leukemias.
Megakaryocyte abnormalities (choice B) can produce platelet disorders, but not deficient bone
resorption.
In multiple myeloma, neoplastic plasma cells (choice C) can cause lytic bone lesions characterized
by excessive resorption of bone.
Abnormally low osteoclast, rather than osteoblast (choice D), function is the problem in osteopetrosis.
- What of the following is characterized by left lower quadrant periumbilical pain in an elderly
person, with the presence of fever, tender abdomen, leukocytosis, nausea, and vomiting?
A. Acute appendicitis
B. Diverticulitis
C. Gallstones
D. Pancreatitis
E. Pyelonephritis
The correct answer is B. Diverticulitis is a disease of the elderly and usually involves the distal
colon. In severe cases, however, the diverticula may extend throughout the colon and up to the
cecum. Inflammation of a cecal diverticulum can closely mimic acute appendicitis. The essentials of
diagnosis for diverticulitis are acute abdominal pain and fever, left lower abdominal tenderness, and
mass. Leukocytosis is commonly present together with nausea and vomiting.
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Acute appendicitis (choice A) is usually a disease of young adults (and sometimes children). It is
rarely seen in the elderly.
Pancreatitis (choice D), pyelonephritis (choice E), and gall bladder disease (choice C), refer pain to
the mid back, lateral back, and right upper quadrant, respectively.
- Which of the following genetic conditions is MOST likely to be the cause of a child born with
with a small head, small eyes, six fingers on each hand, and congenital heart defects?
A. Trisomy 13
B. Trisomy 18
C. Trisomy 21
D. XXY
E. XYY
The correct answer is A. This is a description of Patau’s syndrome or trisomy 13. This disorder is
also associated with severe mental retardation, abnormal forebrain structures, and death within 1 year
of birth. Patau’s syndrome has an incidence of 1:6,000 births, making it the second most common
form of autosomal trisomy.
Trisomy 18 (choice B) is Edwards syndrome, characterized by severe mental retardation, rocker
bottom feet (also sometimes seen in Patau’s syndrome), low-set ears, micrognathia, clenched hands,
prominent occiput, and death within 1 year. Edwards syndrome has an incidence of 1:8,000, making it
the third most common autosomal trisomy.
Trisomy 21 (choice C) is Down syndrome, and is characterized by mental retardation, flat facial
profile, prominent epicanthal folds, simian crease, duodenal atresia, and congenital heart disease.
Down syndrome is the most common autosomal trisomy, with an incidence of 1:700.
XXY (choice D) is Klinefelter’s syndrome and is associated with male hypogonadism and infertility,
eunuchoid body habitus, gynecomastia, and lack of male secondary sexual characteristics.
XYY (choice E) is double Y syndrome. Affected individuals often go undetected, but may be taller
than average and may be more likely to exhibit aggressive, antisocial behavior.
- If a woman 22 weeks pregnant has ankle edema and proteinuria, the presence of which of
the following would determine if she has preeclampsia?
A. Diabetes mellitus
B. Hyperuricemia
C. Hypertension
D. Systemic lupus erythematosus
E. Thrombocytopenia
The correct answer is C. A pregnant patient is considered to be in preeclampsia if she develops
hypertension, proteinuria, and edema. The hypertension is defined as a sustained elevation of blood
pressure of 140 mm Hg systolic or 90 mm Hg diastolic or more in the absence of chronic hypertension
after 20 weeks’ gestation. Eclampsia includes the addition of seizures to the triad. Approximately 7%
of pregnant women develop preeclampsia, typically between 20 weeks’ gestation to 6 weeks
postpartum. Predisposing conditions include preexisting hypertension, diabetes (choice A), and
autoimmune diseases such as lupus (choice D). Laboratory features can include hyperuricemia
(choice B) and thrombocytopenia (choice E), but these are not used to define the presence of
preeclampsia.
7. Which of the following blood components can be expected to increase with disseminated intravascular coagulation? A. Factor V B. Fibrin degradation products C. Fibrinogen D. Plasminogen E. Platelets
The correct answer is B. Disseminated intravascular coagulation (DIC or consumptive
coagulopathy) represents pathologic activation of the coagulation system by another underlying
disease, with consequent consumption and depletion of the cellular and humoral components of the
coagulation cascade. The fibrinolytic mechanisms are also activated, and an uncontrolled cycle of
bleeding and clotting develops. The essentials of diagnosis include underlying serious illness,
hypofibrinogenemia, thrombocytopenia, fibrin degradation products, and prolonged prothrombin time.
As a consequence, levels of all clotting proteins (choices A and C) become depleted, platelet counts
drop (choice E), and the fibrinolytic proteins are depleted also (choice D). Fibrin degradation
products (choice B), which are normally low in the serum, increase markedly because of increased
fibrinolysis seen in this disease; identification of these proteins can be an important indicator of DIC.
- Which of the following additional clinical findings would MOST be associated with a woman
who has oral mucosal swelling, xerostomia, and intense salivary gland destructive
inflammation, as well as antibodies against ribonucleoprotein?
A. Conjunctivitis
B. Goiter
C. Hemolytic anemia
D. Proximal muscle weakness
The correct answer is A. This describes Sjogren’s syndrome, an autoimmune disease characterized
by dry eyes (keratoconjunctivitis) and a dry mouth (xerostomia) caused by destruction of the lacrimal
and salivary glands. Sjogren’s syndrome is also characterized by autoantibody production. The most
diagnostic autoantibodies are those against ribonucleoproteins.
Goiters (choice B) are not typical of Sjogren’s syndrome. Although autoimmune thyroiditis is
associated with Sjogren’s syndrome, ocular involvement is much more characteristic than thyroid
involvement.
Hemolytic anemia (choice C) is not characteristic of Sjogren’s syndrome. Primary autoantibodies,
drugs, and systemic lupus erythematosus may be associated with hemolytic anemia.
Proximal muscle weakness (choice D), in association with autoantibodies, is expected in polymyositis
or dermatomyositis. Although polymyositis may occur in association with Sjogren’s syndrome,
keratoconjunctivitis would be much more common than muscle weakness.
- What phenomenon is responsible when a person sets off the metal detector at the airport,
despite removing watch, belt buckle, and every other obvious source of metal?
A. Argyria
B. Gall stones
C. Hemochromatosis
D. Kidney stones
E. Wilson’s disease
The correct answer is C. Hemochromatosis is an iron storage disorder that can cause cirrhosis (with
increased risk for hepatocellular carcinoma), skin pigmentation, pancreatic damage leading to
diabetes mellitus, and congestive heart failure. These complications are attributable to damage
caused by deposition of iron in tissues; the total body iron in some of these individuals may reach 50
g, sufficient to set off some airport metal detectors.
Argyria (choice A) is a blue-gray skin discoloration related to silver poisoning.
Neither gallstones (choice B) nor kidney stones (choice D) contain metal.
In Wilson’s disease (choice E), copper is deposited in the liver and brain, but not enough to be
detected by metal detectors.
- Which of the following is the explanation for the laboratory findings in an alcoholic with
chronic obstructive lung disease, secondary to cigarette smoking, of persistently lower serum
levels than expected of theophylline which is being used as a bronchodilator, even though the
drug is taken according to schedule?
A. Cirrhosis of the liver
B. Decreased absorption
C. Enhanced liver metabolism
D. Increased urinary clearance
E. Noncompliance
The correct answer is C. Alcohol and smoking normally enhance the cytochrome P450 system in the
smooth endoplasmic reticulum (SER) of the liver. This system is responsible for the metabolism of
drugs, hence, the low theophylline levels are most likely caused by enhanced liver metabolism. The
hepatocyte SER undergoes hyperplasia as a response to alcohol ingestion and synthesizes the
enzyme gamma-glutamyl transferase (GGT). An elevation of GGT would help confirm the likelihood of
increased hepatic drug metabolism as the cause of low drug levels.
Cirrhosis of the liver (choice A) would likely increase the serum levels of theophylline because of poor
metabolism of the drug.
Decreased absorption of the drug (choice B) in the gastrointestinal tract is a possible choice. The
history of excess alcohol intake, chronic smoking, and lack of a history of malabsorption, however,
suggest increased hepatic metabolism.
Increased clearance of theophylline in the urine (choice D) implies an increase in the glomerular
filtration rate, which would not be expected in this patient.
In most circumstances, the lack of an expected response to a medication is because of patient
noncompliance until proven otherwise; however, the question stem rules this out.
- Which of the following could develop with a mucosal neuroma on the lower lip, family
history of medullary thyroid carcinoma, and recent introduction of severe headaches,
perspiration, palpitations, and hypertension?
A. Gastrinoma
B. Insulinoma
C. Parathyroid adenoma
D. Pheochromocytoma
E. Pituitary adenoma
The correct answer is D. This describes multiple endocrine neoplasia, specifically, MEN III (formerly
MEN II b). Features of this autosomal dominant condition include medullary carcinoma of the thyroid,
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pheochromocytoma, and oral and intestinal ganglioneuromatosis (including mucosal neuromas).
Pheochromocytomas typically cause attacks of severe headache, perspiration, palpitations,
hypertension, anxiety, and tremor.
Gastrinomas (choice A) and insulinomas (choice B) are found in MEN I.
Parathyroid adenomas (choice C) are found in MEN I and II.
Pituitary adenomas (choice E) are found in MEN I.
- Which of the following substances is significantly elevated in the serum of a young adult
male with bilateral parotid gland swelling, orchitis, and fever and malaise?
A. Alanine aminotransferase
B. Amylase
C. Aspartate aminotransferase
D. Cortisol
E. Creatine phosphokinase, MB isoenzyme
The correct answer is B. The disease described is mumps, caused by a paramyxovirus. In children,
mumps causes a transient inflammation of the parotid glands, and less commonly the testes,
pancreas, or central nervous system. Mumps tends to be a more severe disease in adults than in
children as it involves the testes (causing orchitis) and pancreas with some frequency. Pancreatic
involvement can cause elevation of serum amylase.
Alanine aminotransferase (ALT) (choice A) and Aspartate aminotransferase (AST) (choice C) are
markers for hepatocellular damage.
Cortisol (choice D) levels are increased in patients with Cushing’s syndrome. This condition is
associated with central obesity, muscle wasting, thin skin, easy bruisability, psychologic changes,
hirsutism, and purple stria. Osteoporosis, hypertension, hyperglycemia, and glycosuria are also noted.
Creatine phosphokinase, MB isoenzyme (CPK-MB) (choice E) is the isoenzyme of CPK that is
relatively specific for the myocardium. This enzyme is increased in the early stages of a myocardial
infarction.
12. Which of the following forms of gastritis would MOST likely be found with a history of longterm use of nonsteroidal antiinflammatory drugs and complaints of heartburn, nausea, and vomiting for several days? A. Acute gastritis B. Chronic antral gastritis C. Chronic fundal gastritis D. Hypertrophic gastritis E. Lymphocytic gastritis
The correct answer is A. Acute gastritis, characterized by patches of erythematous mucosa,
sometimes with petechiae and ulceration, can be seen as a complication of a variety of other
conditions (alcohol use, aspirin and other NSAIDs use, smoking, shock, steroid use, and uremia),
which usually have in common disruption of the mucosal barrier of the stomach.
Chronic antral (type B) gastritis (choice B) is associated with Helicobacter pylori.
Chronic fundal (type A) gastritis (choice C) is associated with pernicious anemia.
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Hypertrophic gastritis (Menetrier’s disease; choice D) is an idiopathic condition characterized by
markedly enlarged mucosal folds.
Lymphocytic gastritis (choice E) is believed to be a gastric manifestation of celiac sprue.
13. What is responsible for mild temporary hyperthyroidism after a person complains of a severe sore throat? A. Diffuse nontoxic goiter B. Grave's disease C. Hashimoto's thyroiditis D. Subacute granulomatous thyroiditis
The correct answer is D. It is due to subacute granulomatous (de Quervain) thyroiditis, which
frequently develops after a viral infection. Microscopically, it is characterized by microabscess
formation within the thyroid, eventually progressing to granulomatous inflammation with
multinucleated giant cells. Clinically, patients may experience fever, sudden painful enlargement of
the thyroid, or symptoms of transient hyperthyroidism. The disease usually abates within 6-8 weeks.
Diffuse nontoxic goiter (choice A) by definition does not produce hyperthyroidism. Goiter is usually
associated with low thyroid function.
The hyperthyroidism of Grave’s disease (choice B) does not spontaneously remit.
Hashimoto’s thyroiditis (choice C) can cause transient hyperthyroidism, but then goes on to cause
hypothyroidism.
- What reaction has occured if after receiving a tuberculosis vaccine, the area becomes
indurated and erythematous, having a 12 mm diameter?
A. Antibody-dependent cell-mediated cytotoxicity
B. Local anaphylaxis
C. T-cell mediated cytotoxicity
D. Type III hypersensitivity
E. Type IV hypersensitivity
The correct answer is E.The tuberculin reaction is an example of delayed-type hypersensitivity (a
form of Type IV hypersensitivity) in which the bulk of the tissue damage is done by macrophages that
are stimulated by a few previously sensitized CD4+ memory T-cells recognizing antigens presented
by the macrophages. In contrast, in T-cell mediated cytotoxicity (choice C, another form of Type IV
sensitivity) the damage is done by CD8+ cytotoxic T-cells that recognize “foreign” cell surface
antigens and directly lyse targeted cells.
Antibody-dependent cell-mediated cytotoxicity reactions (choice A, a form of Type II hypersensitivity)
involves cells coated with a thin layer of antibody that triggers attack by cells (monocytes, neutrophils,
eosinophils, and natural killer cells) that can bind to Fc receptors.
Local anaphylaxis (choice B, a form of Type I hypersensitivity) is caused by the release of vasoactive
substances by mast cells and basophils stimulated by memory (CD4+) T-cells reacting to antigen.
Type III (choice D) hypersensitivity is caused by deposition of circulating antigen-antibody complexes,
often in small blood vessels.
- Which of the following is characterized by extreme weakness, fatigue, nausea, stomach
cramps, hypotensive while sitting and even more on standing, hyperkalemia, increased
freckling around the eyes, and darkening of the palmar creases?
A. Addison’s disease
B. Conn’s syndrome
C. Cushing’s syndrome
D. Secondary adrenal insufficiency
E. Tertiary adrenal insufficiency
The correct answer is A. Addison’s disease usually occurs because of autoimmune destruction of
the adrenal cortex (all three zones are typically involved), resulting in decreased secretion of cortisol,
aldosterone, and adrenal androgens. Hyperpigmentation is the classic physical finding, resulting from
increased serum ACTH caused by loss of negative feedback inhibition by cortisol at the pituitary or
hypothalamus. The increase in pigmentation may occur because the first 13 amino acids of ACTH are
identical to alpha-melanocyte stimulating hormone. Low serum levels of cortisol produce
gastrointestinal symptoms such as nausea, vomiting, and anorexia. Fatigue and weakness are almost
always reported. Blood pressure is usually low and orthostatic hypotension may be present, because
arterioles are less responsive to the constrictor effects of catecholamines in the absence of cortisol.
The cardiovascular symptoms are worsened by the loss of blood volume caused by aldosterone
deficiency. Hyperkalemia is a manifestation of the low serum aldosterone; hyponatremia may also be
present.
Conn’s syndrome (choice B) results from hypersecretion of aldosterone. It is characterized by
hypertension, hypernatremia, and hypokalemia.
Cushing’s syndrome (choice C) occurs because of excessive secretion of cortisol. It is characterized
by central obesity, buffalo hump, moon facies, hypertension, and hypokalemia.
Secondary (choice D) and tertiary (choice E) adrenal insufficiency result in low serum levels of
ACTH. The subsequent hypocortisolism can produce the gastrointestinal complaints and fatigability
but not hyperkalemia. With deficiency of CRH or ACTH, serum aldosterone usually remains in the
normal range, and signs of mineralocorticoid deficiency are not present. Furthermore, low serum
levels of ACTH would not produce hyperpigmentation.
- A 45-year-old man presents to a physician with back pain, facial pain, coarse facial
features, and kyphosis. His laboratory studies show elevated alkaline phosphatase. X-ray
studies demonstrate skull thickening with narrowing of foramina and bowing of the femur and
tibia. Bone biopsy reveals a mosaic pattern of bone spicules with prominent osteoid seams.
Which of the following neoplasms occurs at an increased frequency in patients with this
disorder?
A. Astrocytoma
B. Hodgkin lymphoma
C. Meningioma
D. Non-Hodgkin lymphoma
E. Osteosarcoma
The correct answer is E. The phrase “mosaic pattern” of newly formed woven bone is specific for
Paget disease of bone and is not seen in other bone conditions. The clinical and radiologic
presentation are typical; an increased hat size may also be a clue. In early stages, Paget disease is
characterized by osteolysis, producing patchwork areas of bone resorption with bizarre, large
osteoclasts. In the middle stage of the disease, secondary osteoblastic activity compensates with new
bone formation, producing the mosaic pattern. In late Paget disease, the bones are dense and
osteosclerotic. Paget disease is suspected to be related to prior viral infection, but the cause remains
unknown. Complications include myelophthisic anemia, high output cardiac failure, pain secondary to
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nerve compression, deformities secondary to skeletal changes, and in approximately 1% of patients,
osteosarcoma or other sarcoma, typically involving the jaw, pelvis, or femur.
An increased incidence of astrocytomas (choice A) is associated with tuberous sclerosis.
Hodgkin lymphoma (choice B) is usually a disease of young adults, although older patients may have
the lymphocyte-depleted form.
Meningiomas (choice C) are mostly benign tumors that affect adults, especially women. There may
be an association with breast cancer, possibly related to high estrogen states.
Non-Hodgkin lymphoma (choice D) is more common in AIDS and other immunodeficiency states,
although the incidence in the immunocompetent is increasing.
- Which of the following can be present with swollen and painful toes and knees, morning
low back stiffness, conjunctivitis, as well as mouth and skin ulcerations in a young adult?
A. Gout
B. Lyme disease
C. Reiter’s syndrome
D. Rheumatoid arthritis
E. Septic arthritis
The correct answer is C. This is a description of Reiter’s syndrome. Patients typically present with
the acute onset of arthritis (usually asymmetric and additive), with involvement of new joints occurring
over a period of a few days to 2 weeks. Joints of the lower extremities are the most commonly
involved, but wrists and fingers can also be affected. Dactylitis (sausage digit), a diffuse swelling of a
solitary finger or toe, is a distinctive feature of Reiter’s arthritis and psoriatic arthritis. Tendonitis and
fasciitis are common, as are spinal pain and low back pain. Oligoarthritis, conjunctivitis, urethritis, and
mouth ulcers are the most common features. The mucocutaneous lesions may include balanitis,
stomatitis, and keratoderma blennorrhagicum. Microorganisms that can trigger Reiter’s syndrome
include Shigella spp., Salmonella spp., Yersinia spp., Campylobacter jejuni, and Chlamydia
trachomatis. Most patients are younger males.
Gout (choice A) usually presents as an explosive attack of acute, very painful, monarticular
inflammatory arthritis. Hyperuricemia is the cardinal feature and prerequisite for gout. The first
metatarsophalangeal joint is involved in more than 50% of first attacks.
Lyme disease (choice B), caused by Borrelia burgdorferi, presents with a red macule or papule at the
site of the tick bite. This lesion slowly expands to form a large annular lesion with a red border and
central clearing. The lesion is warm, but usually not painful. The patient also has severe headache,
stiff neck, chills, arthralgias, and profound malaise and fatigue. Untreated infection is associated with
development of arthritis in the large joints (e.g., knees) lasting for weeks to months.
Rheumatoid arthritis (choice D) begins insidiously with fatigue, anorexia, generalized weakness, and
vague musculoskeletal symptoms leading up to the appearance of synovitis. Pain in the affected
joints, aggravated by movement, is the most common manifestation of established rheumatoid
arthritis. Generalized stiffness is frequent, especially in the morning, and is usually greatest after
periods of inactivity. Rheumatoid arthritis is more common in females. The metacarpophalangeal and
proximal interphalangeal joints of the hands are characteristically involved.
Septic arthritis (choice E) is caused by a variety of microorganisms, including Neisseria gonorrhoeae
and Staphylococcus aureus. Hematogenous spread is the most common route in all age groups.
Approximately 90% of patients present with involvement of a single joint, usually the knee. The usual
presentation is moderate to severe pain, effusion, muscle spasm, and decreased range of motion.
- Which of the following antigens would autoantibodies be directed against when there is
symmetrical swelling of the proximal phalangeal joints and large subcutaneous nodules over
the extensor surfaces of both arms of a older woman?
A. Acetylcholine receptor
B. Double stranded DNA
C. Histones
D. IgG
E. Ribonucleoprotein
The correct answer is D. The disease described is rheumatoid arthritis, and the autoantibody is
rheumatoid factor, which is usually an IgM or IgG (or less commonly IgA) directed against the
constant region of autologous IgG.
Autoantibody directed against acetylcholine receptors (choice A) is a feature of myasthenia gravis.
Autoantibody directed against double stranded DNA (choice B) is a feature of systemic lupus
erythematosus.
Autoantibody directed against histones (choice C) is a feature of drug-induced lupus.
Autoantibody directed against ribonucleoprotein (choice E) is a feature of mixed connective tissue
disease.
- What is the BEST explanation for rapid weight gain, buffalo hump formation, prominent
vertical purple abdominal striae, and the increase of fasting blood glucose, plasma levels of
ACTH and cortisol, and also the presence of osteoporosis, hypertension, poor wound healing,
and hypokalemia in an older male?
A. Addison’s disease
B. An ectopic ACTH-secreting tumor
C. Conn’s syndrome
D. Cushing’s disease
E. Primary hypercortisolism
The correct answer is D. This is a description of “Cushingoid” signs and symptoms caused by
hypercortisolism. Although the acute effect of cortisol is to produce lipolysis, patients with chronically
increased cortisol levels develop a characteristic central obesity and buffalo hump. The extremities
are often thinned. The mechanism for the redistribution of body fat is not known but may involve an
interaction between cortisol and insulin. The weight gain with hypercortisolism usually results from
increased appetite. Cortisol excess causes protein catabolism, which leads to poor wound healing,
decreased connective tissue, and fragile blood vessels. The combination of thin skin and fragile blood
vessels leads to abdominal stretch marks (striae) that are characteristically purple in color. Because of
increased gluconeogenesis and decreased peripheral insulin sensitivity, blood glucose may be
increased. Osteoporosis, hypertension, poor wound healing, and hyperkalemia are also commonly
seen. If the hypercortisolism is caused by a functional tumor in the adrenal cortex (primary
hypercortisolism, choice E), plasma concentration of ACTH should be low because of negative
feedback suppression. Increased cortisol and increased ACTH could result from a functional ACTHsecreting
tumor in the pituitary (Cushing’s disease) or an ectopic tumor (such as a small cell
carcinoma of the lung, choice B).
Addison’s disease (choice A) is primary adrenal insufficiency, and whereas plasma ACTH is
increased (producing hyperpigmentation), plasma cortisol and aldosterone are decreased (not
increased) compared with normal.
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Conn’s syndrome (choice C) results from hypersecretion of aldosterone by the adrenal cortex. Some
of the clinical manifestations overlap with Cushing’s disease: for example, both may exhibit
hypertension. In the case of Conn’s syndrome, this is caused by excessive renal sodium and water
reabsorption because of increased aldosterone levels. In Cushing’s disease, it is due in part to the
mineralocorticoid-like effects of high plasma cortisol.
- What condition is marked by dilated cardiomyopathy, slow speech and intellectual
function, fatigue, lethargy, cold intolerance, listlessness, thickened facial features, periorbital
edema, dry, coarse skin, and peripheral edema, and also with low serum levels of T4 and high
ones of TSH?
A. Cretinism
B. Grave’s disease
C. Hyperthyroidism
D. Myxedema
E. Thyroid cancer
The correct answer is D. Myxedema is caused by long-standing hypothyroidism in adults.
Myxedema can result from the many causes of hypothyroidism: Hashimoto’s thyroiditis, idiopathic
primary hypothyroidism, iodine deficiency, drugs, pituitary lesions, hypothalamic lesions, and damage
to the thyroid by surgery or radiation.
Cretinism (choice A) is caused by hypothyroidism in infancy.
Grave’s disease (choice B) usually produces hyperthyroidism.
Hyperthyroidism (choice C) describes the signs and symptoms associated with an overproduction of
thyroid hormone. Because the body’s metabolism is increased,patients often feel hotter than those
around them and can slowly lose weight even though they may be eating more. The weight issue is
confusing sometimes since some patients actually gain weight because of an increase in their
appetite. There is usually fatigue at the end of the day, but have trouble sleeping. Trembling of the
hands and a hard or irregular heartbeat (called palpitations) may develop. These individuals may
become irritable and easily upset. When severe, there can be shortness of breath, chest pain, and
muscle weakness.
Thyroid cancer (choice E) often causes a painless swelling in the region of the thyroid. Thyroid
function tests are usually normal.
- Which of the following occurs after an upper respiratory infection and involves severe
lower back pain, generalized muscle weakness, and distal paresthesia and demyelination, but
there is no appreciable sensory loss and there is minimal residual sequelae?
A. Creutzfeldt-Jakob disease
B. Friedreich ataxia
C. Huntington’s disease
D. Multiple sclerosis
The correct answer is D. This describes Guillain-Barr syndrome, also known as acute idiopathic
inflammatory polyneuropathy. This condition, which typically follows an upper respiratory or other
infection by several days to a month, is caused by an autoimmune attack on the myelin of peripheral
nerves. In this respect, it is most similar to multiple sclerosis, which is an autoimmune attack on the
myelin in the brain and spinal cord. Most cases of Guillain-Barr syndrome resolve spontaneously. A
few patients have recurrences, and rare patients die during the acute episode of respiratory muscle
failure (artificial ventilation may be required).
Creutzfeldt-Jakob disease (choice A) is an Alzheimer-like condition caused by a prion (protein
infectious agent).
11
Friedreich ataxia (choice B) is an autosomal recessive disorder associated with spinocerebellar
degeneration. Ataxia and paralysis are seen beginning in adolescence.
Huntington’s disease (choice C) is an autosomal dominant degeneration of the caudate and frontal
lobes characterized by movement disorder and dementia.
- Which of the following can involve lassitude, myalgia, mylar rash, joint pain, elevated
urinary protein, with the blood showing leukopenia and a high titer of antinuclear antibodies?
A. Generalized fatigue
B. Goodpasture’s syndrome
C. Systemic lupus erythematosus
D. Scleroderma
The correct answer is C. Systemic lupus erythematosus (SLE) is a prototype connective tissue
disease. The diagnosis requires four criteria to be met from a list of 11 possible criteria: malar rash,
discoid rash, photosensitivity, oral ulcers, arthritis, serositis, renal disorder, neurologic disorder,
hematologic disorder, immunologic disorder, and antinuclear antibody. The appearance of a malar or
“butterfly” rash seen in approximately half of all patients is generally the easiest way to diagnose this
condition on the dental boards. Antinuclear antibodies (ANA) are present in 95-100% of cases of SLE;
anti-double-stranded DNA is found in 70% of the cases.
Generalized fatigue (choice A) can occur in anyone, but the presence of the other criteria make SLE
more likely.
Goodpasture’s syndrome (choice B) is characterized by linear disposition of immunoglobulin and
often C3 along the glomerular basement membrane (GBM). Glomerulonephritis, pulmonary
hemorrhage, and occasionally idiopathic pulmonary hemosiderosis occur.
Scleroderma (choice D) is characterized by thickening of the skin caused by swelling and thickening
of fibrous tissue, with eventual atrophy of the epidermis. ANA are often associated with the disease,
but the staining pattern is generally nucleolar.
- Which of the following cancers may develop when there are islands of red tissue noted
above the gastroesophageal junction in situations involving chronic reflux of gastric contents
into the esophagus?
A. Adenocarcinoma of the esophagus
B. Adenocarcinoma of the stomach
C. Sarcoma of the esophagus
D. Sarcoma of the stomach
E. Squamous cell carcinoma of the esophagus
The correct answer is A. The lesion is Barrett’s esophagus, which is related to chronic reflux of
gastric contents into the esophagus. This lesion predisposes for the development of adenocarcinoma
of the distal esophagus, which is the most serious complication of Barrett’s esophagus. The
development of adenocarcinoma of the esophagus is approximately 40 times higher in patients with
Barrett’s esophagus compared with those without the lesion.
Conditions predisposing for adenocarcinoma of the stomach (choice B) include chronic atrophic
gastritis, pernicious anemia, and postsurgical gastric remnants.
Sarcoma of the esophagus (choice C) or stomach (choice D) is rare.
Plummer-Vinson syndrome predisposes for squamous cell carcinoma of the esophagus (choice E).
- Which of the following when removed from the diet will help improve a history of weight
loss, diarrhea, flatulence, greasy stools, and increased fecal fat and marked atrophy of villi?
A. Beef
B. Eggs
C. Potatoes
D. Tomatoes
E. Wheat
The correct answer is E. This describes celiac sprue which is caused by an allergic, immunologic, or
toxic reaction to the gliadin component of gluten from wheat, as well as rye, barley, and oats, but not
rice or corn. The symptoms and pathologic changes usually reverse with complete removal of gliadin
from the diet. Therapeutic failures are frequently caused by hidden wheat in the diet. Patients with
celiac disease have an increased risk for developing gastrointestinal lymphoma. The classic signs and
symptoms of celiac sprue include weight loss, flatuence, greasy stools, and increased fecal fat. A
diagnosis can be confirmed when clinical improvement is made on a gluten-free diet.
- Which of the following is the MOST likely explanation for a rash in a leukemic patient that
consists of multiple erythematous patches on the arms, legs, palms, and soles, some of which
show central clearing and surrounding ring formation?
A. Urticaria
B. Erythema multiforme
C. Kaposi’s sarcoma
D. Psoriasis
The correct answer is B. The presence of erythematous patches with central clearing, known
clinically as target lesions, is associated with erythema multiforme. Both erythema multiforme and its
severe, life-threatening version, known as Stevens-Johnson syndrome, are produced by immune
complex deposition in dermal blood vessels. In approximately 50% of patients, no specific
precipitating cause is identified. In the remainder of patients, however, a variety of causes have been
implicated, including certain infections (herpes simplex, enteroviruses, Mycoplasma pneumoniae,
Chlamydia, histoplasmosis), drugs, neoplasia, sarcoidosis, and foods. Some penicillins and
corticosteroids can also cause this condition.
Urticaria (choice A) causes wheals that are intensely pruritic, but does not produce target lesions.
Kaposi’s sarcoma (choice C) causes purple lesions with no target lesions.
Psoriasis (choice D) causes erythematous plaques with silvery scales but does not produce target
lesions.
- A 72-year-old man with a significant smoking history presents with dyspnea, facial
erythema, and facial, truncal, and arm edema with prominence of thoracic and neck veins.
Chest x-ray reveals a mass in the right mediastinum with adenopathy. Which of the following
is the most likely diagnosis?
A. Adenocarcinoma
B. Hodgkin lymphoma
C. Large cell carcinoma
D. Non-small cell carcinoma
E. Small cell carcinoma
The correct answer is E. Superior vena cava (SVC) syndrome is characterized by obstruction of
venous return from the head, neck, and upper extremities. More than 85% of cases of SVC syndrome
are related to malignancy. Bronchogenic carcinomas (most commonly small cell cancer and
13
squamous cell cancer) account for more than 80% of these cases. Among bronchogenic carcinomas,
the most common causes of SVC syndrome (in order of frequency) are small cell carcinoma,
epidermoid carcinoma, adenocarcinoma (choice A), and large cell carcinoma (choice C).
Lymphomas such as Hodgkin disease (choice B) and non-Hodgkin lymphoma are uncommon causes
of SVC syndrome. Rare tumors associated with SVC syndrome include primary leiomyosarcomas and
plasmacytomas. Infectious etiologies include tuberculosis, syphilis, and histoplasmosis. SVC
syndrome can also occur as a result of an enlarged goiter, and from thrombus formation caused by
indwelling intravenous lines or pacemaker wires.
Non-small cell carcinoma (choice D) is not commonly associated with SVC syndrome.
27. What can be present when there is digital clubbing and tenderness over the distal ends of the radius, ulna, and fibula? A. Gastrointestinal cancer B. Liver cancer C. Lung cancer D. Renal cancer E. Testicular cancer
The correct answer is C. This patient has the finger clubbing and hypertrophic pulmonary
osteoarthropathy that can be associated with bronchogenic carcinoma (other than squamous cell
carcinoma), benign mesothelioma, and diaphragmatic neurilemmoma. X-ray of the bones generally
shows formation of new periosteal bone; arthritis may be present. The etiology of these changes
remains a mystery. An alert clinician may identify a cancer at an earlier, potentially curable stage by
investigating a possible paraneoplastic syndrome. Digital clubbing is caused by chronically low
oxygen levels. This condition affects the fingers and toes in which proliferation of the distal tissues,
especially the nail beds, results in broadening of the extremities of these digits. The affected nails are
abnormally curved and shiny.
- Which of the following lesions are present in an adult with newly diagnosed tuberculosis?
A. A single lesion in a lung apex
B. A single lesion in the gastrointestinal tract
C. A single lesion subjacent to the pleura
D. A lesion subjacent to the pleura in the lower part of an upper lobe and active disease in the
mediastinal lymph nodes
E. Multiple tiny masses throughout the body
The correct answer is A. Because tuberculosis is transmitted primarily by “droplet” transmission by
way of the nasopharynx, it is essential that the dental student understand the basic principles of
tuberculosis. Primary tuberculosis infection characteristically involves the lung subjacent to the pleura
in either the lower part of the upper lobe or the upper part of a lower lobe of one lung. The mediastinal
nodes are also usually involved (choice D), rather than having a single lesion subjacent to the pleura
(choice C) without lymph node involvement. Roughly 80% of newly diagnosed pulmonary
tuberculosis cases in adults are actually caused by reactivation of an often clinically unsuspected
infection acquired years to decades previously. The reinfection site usually is in the apex of the lung.
The source of reinfection is usually a Gohn complex, or calcified granuloma of giant cells,
mycobacteria leukocytes, and fibrous cells.
The lungs are not the only site where tuberculosis can occur (it can occur throughout the body), and
isolated gastrointestinal involvement (choice B) is (uncommonly) also seen.
Miliary tuberculosis (rare) is a widely disseminated and dangerous form of tuberculosis characterized
by small lesions throughout the body (choice E). It is more common in immunocompromised patients.
- Which of the following is involved when there is excessive bleeding after labor, and the
laboratory studies demonstrate decreased platelets, prolonged prothrombin time and partial
thromboplastin time, and increased fibrin split products?
A. Disseminated intravascular coagulation
B. Hemophilia A
C. Severe liver disease
D. Vitamin K deficiency
E. Von Willebrand’s disease
The correct answer is A. Thsi is a description of disseminated intravascular coagulation (DIC), a
feared and often life-threatening complication of many other disorders, including amniotic fluid
embolism, infections (particularly gram-negative sepsis), malignancy, and major trauma. This is
suspected when a decrease in platelets and a prolongation of PT and PTT times are observed. The
observed hematologic abnormalities are caused by consumption of platelets and clotting factors,
caused by extensive microclot formation with accompanying fibrinolysis (reflected by the increased
fibrin split products).
Hemophilia (choice B) alters the PTT without affecting the other indices.
Severe liver disease (choice C) produces alterations comparable to those in vitamin K deficiency;
platelets can also be decreased secondary to a generalized metabolic marrow dysfunction, but fibrin
split products would not be increased.
Vitamin K deficiency (choice D) is associated with alterations in PT and PTT, but platelets will not be
decreased, nor will fibrin split products be increased.
Von Willebrand’s disease (choice E) produces impaired platelet adhesion and increases the bleeding
time and the PTT, but will not produce the other features described.
- Which of the following can account for a child developing fever, conjunctivitis,
photophobia, cough, white spots on a bright red background on the buccal mucosa, and a
rash that begins around the hairline, then spreads to the trunk and extremities?
A. Aphthous ulcers
B. Herpetic stomatitis
C. Laryngeal papillomas
D. Measles
E. Oral thrush
The correct answer is D. This description is of measles, with the appearance of Koplik’s spots (white
spots on the buccal mucosa) followed by a rash beginning along the neck and hairline and spreading
to the trunk and extremities. The sequela of this condition may be postinfectious encephalomyelitis
that can follow infection with measles, varicella, rubella, mumps, influenza, or vaccination with
vaccinia vaccine or rabies vaccine derived from nervous tissue.
Aphthous ulcers (choice A) are easy to recognize because they are round ulcerations with yellowgray
fibrinoid centers surrounded by red halos.
Herpetic stomatitis (choice B) is common, mild, short-lived, and requires no intervention. There is an
initial burning followed by small vessicles that rupture to form scabs.
Laryngeal papillomas (choice C) are common lesions of the larynx and other sites where ciliated and
squamous epithelia meet. Hoarseness progresses to stridor over the course of weeks to months.
Oral thrush (choice E) is associated with the development of painful, creamy white, curd- like patches
overlying erythematous mucosa.
- What is present when an elderly person can no longer recognize people and common
objects, plan activities, and wanders with an absent look on their face, but who is still happy,
yet frustrated by the memory loss, and speech is limited to simple two- or three-word
sentences?
A. Alzheimer’s disease
B. Amnestic disorder
C. Clinical depression
D. Substance-induced persisting dementia
E. Parkinson’s disease
The correct answer is A. This is a description of dementia of the Alzheimer’s type. A gradual onset
of symptoms, general pervasive memory deficit, difficulties with language, and inability to plan,
leading to severe impairment of daily functioning are all characteristic of dementia of the Alzheimer’s
type.
Amnestic disorder (choice B) is limited to memory problems; and not cognitive dysfunction, such as
alterations in language and the loss of the ability to plan.
Clinical depression (choice C) is associated with feelings of helplessness and hopelessness.
Cognitive function is not impaired.
The diagnosis of substance-induced persisting dementia (choice D) requires evidence of a history of
substance abuse. It is the second most likely diagnosis, however, and should be carefully explored.
Parkinson’s disease (choice E) is associated with develpment of dyskinesia, postural instability,
moonlike facies, and difficulty performing daily activities.
- Which of the following substances would be MOST likely be elevated due to the
development of large osteoblastic bone lesions in a patient with prostate cancer?
A. Prostatic acid phosphatase
B. Prostate specific antigen
C. Serum alkaline phosphatase
D. Serum uric acid
E. Leukocytes
The correct answer is C. Osteoblastic cells respond to metastatic prostate carcinoma by forming
bone (osteoid), and secreting alkaline phosphatase, which is believed to initiate or facilitate
mineralization.
Prostatic acid phosphatase (choice A) and prostatic-specific antigen (choice B) are synthesized by
the tumor and would most likely be elevated; however, they are elevated because of the prostatic
cancer independent of the bony metastasis. Serum uric acid (choice D) would be expected to be
seen in patients with gout. White blood cells (choice E) can be elevated by a bacterial infection,
rheumatoid arthritis, and several medications, including glucocorticoids and lithium. In other words,
elevated white blood cells is often a nonspecific indicator.
- Which of the following pair of hormones regulates the hormone responsible for a middleaged
man experiencing gradual coarsening of facial features, progressive protrusion of the
lower jaw, and having to wear larger shoes and gloves?
A. Dopamine and norepinephrine
B. LH and hCG
C. Prolactin and FSH
D. Somatostatin and GHRH
E. TSH and ACTH
The correct answer is D. The disease described is acromegaly, which is typically produced by a
growth hormone-secreting pituitary adenoma. Growth hormone synthesis is predominantly regulated
by hypothalamic GHRH (growth hormone-releasing hormone), and its pulsatile secretion is
predominantly regulated by hypothalamic somatostatin. Clinical features of acromegaly include
excessive growth of hands and feet in adults, protusion of the lower jaw, coarsening of facial features,
and a deeper voice.
Dopamine and norepinephrine (choice A) are catecholamines that regulate smooth muscle tone and
cardiac function.
Choice B is incorrect because luteinizing hormone (LH) regulates sex steroid hormone production by
testes and ovaries; human chorionic gonadotropin (hCG) is produced by the placenta and has actions
similar to LH.
Choice C is incorrect because prolactin regulates menstruation and lactation, whereas follicle
stimulating hormone (FSH) regulates ovarian and testicular function.
Choice E is incorrect because thyroid stimulating hormone (TSH) regulates secretion of thyroid
hormones and adrenocorticotropin (ACTH) regulates glucocorticoid secretion.
- Which of the following tissues or organs may be associated with hyperplasia and
neoplastic proliferation if there is fatigue, feeling of constant coldness, diffusely enlarged and
rubbery thyroid gland, while laboratory tests show low T3 and T4, high TSH, large numbers of
lymphocytes of all degrees of maturation, a few abnormal follicular cells with eosinophilic
granular cytoplasm, and only rare normal follicular cells?
A. Colon
B. Esophagus
C. Peripheral nerve
D. Skin
E. Thymus
The correct answer is E. The thyroid disease is Hashimoto’s thyroiditis, an autoimmune disease in
which the thyroid parenchyma is destroyed by a lymphocytic infiltrate. The infiltrate typically contains
mature follicles; the remaining scanty follicular cells often have eosinophilic granular cytoplasm and
are called Hurthle cells or oncocytes. Clinically, patients usually have hypothyroidism, although brief
periods of hyperthyroidism (“Hashitoxicosis”) may also be seen. Like myasthenia gravis, Hashimoto’s
disease may be associated with thymic disorders, including thymic hyperplasia, benign thymomas,
and malignant thymomas.
Colon (choice A) cancer is associated with ulcerative colitis and adenomatous polyps.
The risk for esophageal cancer (choice B) is increased with Barrett’s esophagus and in Plummer-
Vinson syndrome.
You should associate neurofibromas of peripheral nerve (choice C) with cafe au lait spots on the skin.
Skin cancer (choice D) occurs with greater frequency in association with xeroderma pigmentosa and
actinic keratosis.
- What is occuring when an esophagus is dilated, kinked, tortuous, partly filled with
undigested foods, and is associated with chronic dysphagia?
A. Achalasia
B. Barrett’s esophagus
C. Hiatal hernia
D. Plummer-Vinson syndrome
E. Zenker’s diverticulum
The correct answer is A. Achalasia (from the Greek “unrelaxed”) is a disease of ganglion cells in the
esophageal myenteric plexus causing a failure of relaxation in the lower esophageal (cardiac)
sphincter. The cause of achalasia is usually not determined. The peristaltic waves in the esophagus
stop before the sphincter, and the food collects in the esophagus, which becomes dilated and
elongated.
Barrett’s esophagus (choice B) is metaplastic replacement of the squamous esophageal epithelium
with columnar epithelium. Barrett’s esophagus is an important risk factor for esophageal
adenocarcinoma.
Hiatal hernia (choice C) is a protrusion of the stomach into the thorax by way of the diaphragmatic
hiatus, at the lower esophageal sphincter. Although hiatal hernia can produce gastroesophageal
reflux, the esophagus does not become distended and food passes normally into the stomach.
Plummer-Vinson syndrome (choice D) is a constellation of physical findings associated with severe
iron-deficiency anemia including koilonychia, atrophic glossitis, and dysphagia caused by atrophy of
the pharyngeal mucosa and mucosal webs in the upper esophagus.
Zenker’s diverticulum (choice E) is an oropharyngeal diverticulum occurring at the junction of the
pharynx and esophagus which occurs because of wall weakness in the esophagus at this location,
and may produce dysphagia.
- What is involved in a smoker with scant clear mucoid sputum, quiet sounding chest,
hemoptysis, weight loss, detruction of alveolar septae around the respiratory bronchioles,
with marked enlargement of the airspaces, and heavy deposits of anthracotic pigment?
A. Asthma
B. Chronic bronchitis
C. Emphysema
D. Pulmonary hypertension
E. Silicosis
The correct answer is C. Emphysema is a pulmonary disease characterized by enlargement of the
alveolar airspaces caused by destruction of the septae without consequent fibrosis. The gross
appearance of emphysematous lungs is characteristic: alveoli are sufficiently dilated to allow
visualization with the naked eye and destruction of structural support to lymphatic vessels produces
heavy pigment deposition in the tissue. Microscopic findings that confirm the diagnosis include
enlarged, round airspaces with club-like ends of broken septae sticking into the alveoli. There is scant
clear mucoid sputum. The chest is very quiet without adventitious sounds.
Asthma (choice A) is a disease of airway hyperreactivity and is characterized by hypertrophy of the
bronchial basement membranes and smooth muscle, with glandular hyperplasia and thick mucus
plugs in the bronchi. Wheezing will be heard on expiration.
Chronic bronchitis (choice B) produces marked hypersecretion of mucopurulent mucus in the large
airways and can be identified by hypertrophy of mucous glands in the bronchi and goblet cell
hyperplasia in the smaller airways. The chest is noisy with rhonci invariably present. Wheezing is
common.
Pulmonary hypertension (choice D) affects neither the airways nor the alveoli. It is characterized by
thickening of the arterial smooth muscle with intimal hyperplasia and fibrosis. Atherosclerotic changes
in the normally plaque-free larger pulmonary arteries may be seen.
Silicosis (choice E), one of the forms of pneumoconiosis, is an interstitial fibrosing disease that
produces thick pleural scars and dense nodules of collagen that may calcify. The silica particles may
be visualized within the nodules using polarized light.
37. What presents with painful widespread erosions on the mucous membranes with friability, no well-defined borders, acantholysis, and with direct immunofluorescence demonstrate an intraepidermal band of IgG and C3? A. Bullous pemphigoid B. Dermatitis herpetiformis C. Herpes simplex I D. Herpes simplex II E. Pemphigus vulgaris
The correct answer is E. This is a description of pemphigus vulgaris, in which autoantibody directed
against transmembrane cadherin adhesion molecules induces acantholysis (breakdown of epithelial
cell-cell connections) with resulting intraepidermal blister formation. It has an insidious onset of flaccid
bullae in crops or waves. It may develop spontaneously or following triggers such as drugs (thiols,
penicillamine), physical injury (burns), cancer, pregnancy, other skin diseases, and emotional stress.
Pemphigus vulgaris is a relatively rare blistering disease; it is seen more commonly in patients with
Jewish or Mediterranean heritage. The epidermis at the edge of these erosions is often easily
disrupted by sliding pressure (Nikolsky sign). Pemphigus vulgaris begins in the mouth in 50% of
cases. Acantholysis is seen on biopsy.
Bullous pemphigoid (choice A) is characterized by deeper blisters occurring at the dermal-epidermal
junction.
Dermatitis herpetiformis (choice B) is characterized by severe, intense pruritus and groups of papules
and vesicles.
Herpes simplex I (choice C) or II (choice D) can show multinucleated giant cells on scrapings of the
ulcer base.
- Which of the following thyroid diseases is most likely related to restlessness, fever,
profuse sweating, marked tachycardia and tremor during labor, later developing delirium,
nausea, vomiting, and abdominal pain between contractions?
A. Follicular carcinoma
B. Grave’s disease
C. Hashimoto’s thyroiditis
D. Hypertensive urgency
E. Papillary carcinom
The correct answer is B. This is a description of a thyrotoxic crisis that occurs most commonly in
untreated or inadequately treated Grave’s disease. The onset is typically abrupt and may be
precipitated by stressors that can include infection, trauma, radioiodine treatment, and childbirth. The
condition, if unrecognized, may progress to congestive cardiac failure, pulmonary edema, and death.
Both follicular (choice A) and papillary (choice E) carcinomas of the thyroid gland are usually
nonsecretory and consequently do not produce hyperthyroidism.
Hashimoto’s thyroiditis (choice C) is an autoimmune thyroiditis that may transiently produce
hyperthyroidism before producing hypothyroidism, but thyrotoxic crisis is not usually a feature.
Hypertensive urgency (choice D) is a situation in which blood pressure must be reduced in a few
hours. Most patients are asymptomatic with severe hypertension (systolic > 220 mmHg or diastolic >
125 mmHg)
- Which of the following is the most probable etiology for a young person with acute
bacterial endocarditis limited to the tricuspid valve?
A. Congenital heart disease
B. Illicit drug use
C. Rheumatic fever
D. Rheumatoid arthritis
E. Rheumatic heart disease
The correct answer is B. The most probable etiology of bacterial endocarditis involving the tricuspid
valve is illicit intravenous drug use, which can introduce skin organisms into the venous system that
then attack the tricuspid valve. Staphylococcus aureus accounts for 60-90% of cases of endocarditis
in intravenous drug users. This is an important concept for dentists because some patients with drug
seeking behaviors, such as the intravenous drug abuser, may present to a dental office in search of
narcotic medications.
The endocarditis associated with congenital heart disease (choice A) typically involves either
damaged valves or atrial or ventricular septal defects. The tricuspid valve is not particularly
vulnerable.
Rheumatic fever (choice C) most commonly damages the mitral and aortic valves, and tricuspid
damage is usually less severe and seen only when the mitral and aortic valves are heavily involved.
Consequently, secondary bacterial endocarditis involving only the tricuspid valve in a patient with a
history of rheumatic fever would be unusual.
Rheumatoid arthritis (choice D) is not associated with bacterial endocarditis, unless there is an
association with SLE.
Rheumatic heart disease (choice E) which occurs after rheumatic fever and again involves mainly the
mitral and aortic valves.
- What is the specific mechanism by which death is produced from breathing carbon
monoxide in a closed space?
A. Damage to the plasmalemma
B. Decreased oxygen-carrying capacity of blood
C. Increased calcium transport into mitochondria
D. Poisoning of oxidative phosphorylation
E. Rupture of lysosomes
The correct answer is B. Carbon monoxide has a very high affinity for hemoglobin, and binds, nearly
irreversibly, in such a manner that oxygen cannot bind, drastically decreasing the oxygen-carrying
capacity of the blood. Carbon monoxide also causes the oxygen-hemoglobin dissociation curve to
shift to the left, making oxygen more difficult to unload. Traditionally, carbon monoxide poisoning have
been described as having “cherry red” blood and skin, but this change is somewhat unreliable in real
life.
Choices A, C, and E list secondary changes that are commonly observed in injured cells, no matter
what the cause of the injury.
Cyanide acts by poisoning oxidative phosphorylation (choice D).
41. Which of the following clinical features would be most likely to be present when thyroid function tests reveal increased TSH, decreased total T4, decreased free T4, and decreased T3 uptake? A. Diarrhea B. Heat intolerance C. Hyperactivity D. Palpitations E. Weight gain
The correct answer is E. The laboratory studies are typical for primary hypothyroidism, in which the
thyroid fails to produce adequate T4 despite appropriate TSH signals from the pituitary gland. Clinical
features of hypothyroidism include weight gain, cold intolerance, hypoactivity, fatigue, lethargy,
decreased appetite, constipation, weakness, decreased reflexes, facial and periorbital myxedema, dry
and cool skin, and brittle hair.
In contrast, diarrhea (choice A), heat intolerance (choice B), hyperactivity (choice C), and
palpitations (choice D) are features of hyperthyroidism.
42. Which of the following findings would be MOST consistent for a young person in a coma having an acetone-like odor? A. Alcohol intoxication B. Diabetic hyperosmolar coma C. Diabetic ketoacidosis D. Heroin overdose E. Profound hypoglycemia
The correct answer is C. The smell of acetone on the breath of a comatose person is an important,
rapid diagnostic clue that strongly suggests ketoacidosis and is usually seen in patients with poorly
controlled type 1 diabetes mellitus. Other features of diabetic ketoacidosis include high blood glucose,
increased serum osmolality, hypovolemia, acidosis, and electrolyte imbalance. It is important to note
that diabetic ketoacidotic coma is usually preceded by a day or more of polyuria and polydipsia
associated with marked fatigue, confusion, and nausea.
In alcohol intoxication (choice A), the breath will smell like alcohol. Some may confuse a patient with
diabetes in ketoacidosis as being “drunk,” however, because of the similar smell.
Diabetic hyperosmolar coma (choice B) usually is seen in older patients with type 2 diabetes mellitus
and is not characterized by ketoacidosis. Because there is no acetone production, there is no specific
scent to the breath. In heroin overdose (choice D), no acetone production occurs and there is no
specific scent to the breath. In hypoglycemic coma (choice E), which can occur in diabetics with
insulin overdose, no acetone production occurs and there is no specific scent to the breath.
- A 24-year-old man presents with complaints of itching on his arms and face. He states that
he took four 500-mg capsules of amoxicillin 1 hour before a dental procedure. Physical
examination reveals well circumscribed wheals with raised, erythematous borders and
blanched centers. Which form of hypersensitivity is this patient probably exhibiting?
A. Acute serum sickness (Type III)
B. Antibody-dependent cell-mediated cytotoxicity (Type II)
C. Antireceptor antibodies (Type II)
D. Delayed type hypersensitivity (Type IV)
E. Immediate type hypersensitivity (Type I)
The correct answer is E. Urticaria (hives) is a good example of a local anaphylaxis reaction that is
classified as a Type I hypersensitivity reaction. Type I hypersensitivity reactions involve preformed IgE
antibody bound to mast cells or basophils that release vasoactive and spasmogenic substances when
they react with antigens. Certain allergens, especially drugs, insect venoms, latex, and foods may
induce an IgE antibody response, causing a generalized release of mediators from mast cells leading
to a systemic reaction.
Acute serum sickness (choice A) is now uncommon but was formerly seen when animal sera were
used for passive immunization. Serum-like sickness has also been seen in patients receiving
cephalosporins, such as cefaclor.
The eosinophil-mediated cytotoxicity against parasites is an example of antibody-dependent cellmediated
cytotoxicity (choice B).
Myasthenia gravis is an example of a disease caused by antireceptor antibodies (choice C).
The tuberculin (PPD) reaction used to test for tuberculosis exposure is an example of delayed-type
hypersensitivity (choice D).
- Which of the following notations in a chart indicates the greatest likelihood that a 1-cm,
flat,white patch on the buccal mucosa will progress to a malignancy?
A. Hairy leukoplakia
B. Leukoplakia
C. Linea alba
D. Oral thrush
E. Squamous papilloma
The correct answer is B. Leukoplakia is a white plaque on the oral mucosa for which a more specific
diagnosis cannot be rendered. For example, unlike oral candidiasis the white lesion cannot be
removed by rubbing the oral mucosal surface. Leukoplakia is often associated with hyperkeratosis
and may or may not show dysplastic squamous epithelium. On average, 2-6% represent either
dysplasia or early invasive squamous cell carcinoma.
Hairy leukoplakia (choice A) is an oral infective lesion seen almost exclusively in patients with HIV
infection. It is a fluffy, white, hyperkeratotic lesion in which a destructive piling up of keratotic squames
is seen. Hairy leukoplakia is associated with viral infection, mostly EBV, HPV, or HIV. It does not
progress to cancer.
Linea alba (choice C) is a linear white area on the buccal mucosa formed from hyperkeratosis due to
occlusion, and may be excessive in those that clench or grind.
Oral thrush (choice D) is a superficial candidal infection, typically occurring in immunosuppressed or
very young patients. Thrush is an infectious, non-neoplastic disease.
Squamous papilloma (choice E) is a benign human papillomavirus (HPV) infection of the oral
mucosa. Typically associated with HPV genotypes 6 and 11, squamous papilloma only rarely
progresses to squamous carcinoma.
- Which of the following is present in a elderly person that has thin arms and legs, a swollen
abdomen, red tongue, dry, thin, and slightly yellow skin, gynecomastia, testicular atrophy,
multiple spider angiomas, tremor, yellow discoloration of sclera, and short-term memory loss?
A. Bronchogenic carcinoma
B. Colon carcinoma
C. Congestive heart failure
D. Type 2 diabetes mellitus
E. Hepatic cirrhosis
The correct answer is E. The physical examination is typical for an alcoholic with advanced hepatic
cirrhosis. It is important to recognize these symptoms, as these patients are notorious for
“underestimating” and even denying their alcohol use.
Bronchogenic carcinoma (choice A) typically presents with cough or respiratory changes, but can
present with mass effects in the chest or involvement of mediastinal nerves or vessels.
Colon cancer (choice B) typically presents with changes in the stool or bowel habits.
Congestive heart failure (choice C) is typically heralded by shortness of breath or peripheral edema,
or both.
Type 2 diabetic patients (choice D) are typically obese and present with usual signs and symptoms of
diabetes, such as polyuria, polydipsia, and polyphagia (but not ketoacidosis).
- Which of the following laboratory tests is performed following a head injury so as to
differentiate between nephrogenic and neurogenic diabetes insipidus?
A. Creatinine in a 24-hour urine collection
B. Urine osmolality after vasopressin administration
C. Serum renin after infusion of hypotonic saline
D. Serum sodium after infusion of hypertonic saline
The correct answer is B. Diabetes insipidus is characterized by the excretion of abnormally large
volumes of dilute urine (polyuria) with a commensurate increase in fluid intake (polydipsia). There are
two types, neurogenic and nephrogenic. The most common type is neurogenic diabetes insipidus,
which is caused by inadequate secretion of antidiuretic hormone (ADH) or vasopressin. In the
absence of ADH, a brisk diuresis results; the osmolality of the urine may be extremely low. Many with
neurogenic (central) diabetes insipidus have a history of head trauma, brain tumors, or brain
infections that damage the hypothalamus or neurohypophysis. Nephrogenic diabetes insipidus, which
presents in much the same way, can be seen in association with certain renal diseases caused by a
defect in the renal V2 vasopressin receptor, Gs protein, or other steps in the formation of cyclic AMP.
Plasma levels of vasopressin are usually increased, because of the hyperosmolarity of the serum.
Water deprivation will fail to increase urine osmolarity in neurogenic and nephrogenic diabetes
insipidus. Because V2 receptors are functional in neurogenic diabetes insipidus, however,
administration of exogenous ADH will still concentrate the urine, whereas this would be ineffective in
nephrogenic diabetes insipidus.
Measurement of creatinine (choice A) in a 24-hour urine collection, coupled with plasma creatinine
values and the urine flow rate can be used to approximate glomerular filtration rate.
Renin secretion would be inhibited by infusion of hypotonic saline (choice C) in neurogenic and
nephrogenic diabetes.
Serum sodium (choice D) would rise with infusion of hypertonic saline in either type of diabetes
insipidus.
- Which of the following laboratory results would be expected in a child with 2 standard
deviations below the expected mean height, delayed bone maturation, goiter, and a point
mutation in the thyroid hormone receptor?
A. Decreased radioactive iodine uptake test
B. Increased plasma T4 concentration
C. Decreased plasma TSH concentration
D. Increased basal metabolic rate
The correct answer is B. Generalized resistance to thyroid hormone is a rare genetic abnormality
(Refetoff syndrome). It results from mutations of the thyroid hormone receptor gene. Depending on
the severity of the disorder, patients may be only mildly affected or may exhibit striking hypothyroid-
23
like symptoms including decreased basal metabolic rate (BMR) (not increased, choice D). Growth
can be stunted, there may be deaf mutism, and attention span may be short. Because the thyroid
hormone resistance is generalized, the normal negative feedback effects of T4 and T3 at the
hypothalamus and pituitary are also deficient. This would lead to an increased plasma TSH
concentration (not decreased, choice C). Because of the increase in plasma TSH, iodine trapping by
the thyroid follicular cells will be increased, leading to an increase in radioactive iodine uptake test
(RAIU) (not decreased, choice A) and an increase in serum T4.
