Step Deck Flashcards
What is the pharmacological treatment for preeclampsia or eclampsia to prevent seizures?
IV magnesium sulfate
Magnesium sulfate is used to prevent seizures in patients with preeclampsia or eclampsia.
What is the treatment for preeclampsia with severe features, eclampsia, or HELLP syndrome?
Antihypertensives, magnesium, and delivery*
This treatment approach addresses the critical conditions associated with severe preeclampsia and HELLP syndrome.
Which tocolytic agent works by competing with Ca2+ for muscle depolarization (e.g. myometrium)?
Magnesium sulfate
Magnesium sulfate acts as a tocolytic by affecting calcium’s role in muscle contraction.
Eclampsia is defined as _______.
preeclampsia with seizures
Eclampsia is a severe complication of preeclampsia characterized by the occurrence of seizures.
What are signs of end-organ dysfunction due to preeclampsia?
Pulmonary edema, liver pain (RUQ), headaches, and vision changes
These symptoms indicate serious complications arising from preeclampsia.
What pregnancy complication may be treated with benzodiazepines?
Eclampsia (not first line)
Benzodiazepines are not the first-line treatment but may be used in eclampsia management.
What may be the cause of RUQ pain in preeclampsia?
Liver swelling (stretches liver capsule)
RUQ pain is often a result of liver swelling associated with preeclampsia.
Symptoms of magnesium toxicity include _______.
hypocalcemia and cardiac arrest
Monitoring for magnesium toxicity is crucial during treatment with magnesium sulfate.
What are the drugs of choice to lower BP in severe preeclampsia (maternal hypertensive crisis > 160/110)?
- IV Labetalol
- IV Hydralazine
- PO Nifedipine
These medications are effective in managing severe hypertension in pregnant patients.
What is ramelteon?
Ramelteon is a melatonin receptor agonist used to treat insomnia.
How does ramelteon compare to other hypnotics?
Ramelteon has relatively few side effects and is safe to use in geriatric patients.
What are the side effects of nonbenzodiazepine hypnotics in elderly patients?
Elderly patients are more sensitive to side effects such as cognitive impairment, headache, and delirium.
What is the primary use of nonbenzodiazepine hypnotics?
Nonbenzodiazepine hypnotics are primarily used for the treatment of insomnia.
How do nonbenzodiazepine hypnotics affect the sleep cycle compared to benzodiazepines?
Nonbenzodiazepine hypnotics are less likely to affect the sleep cycle compared to benzodiazepines.
What are the side effects of benzodiazepines in elderly patients?
Elderly patients are more sensitive to side effects such as somnolence, confusion, and disorientation.
What drug class should be avoided when treating delirium?
Benzodiazepines should be avoided when treating delirium.
What sleep disturbance is associated with bupropion use?
Insomnia is associated with bupropion use.
Why are TCAs relatively contraindicated in elderly patients?
TCAs are relatively contraindicated due to severe anticholinergic and antihistamine effects.
Can benzodiazepines be used to treat insomnia?
Benzodiazepines may be used as a hypnotic to treat insomnia, but they are not first line treatment due to physical dependence.
What is botulinum toxin?
Botulinum toxin is an exotoxin from Clostridium botulinum that cleaves SNARE proteins required for neurotransmitter (ACh) release.
Which neurotransmitter’s release is prevented by the botulinum toxin from Clostridium botulinum?
Acetylcholine.
What effect does Clostridium botulinum toxin have on compound muscle action potential (CMAP)?
It can result in a decreased compound muscle action potential (CMAP) following motor nerve stimulation.
What is the pathophysiology of foodborne botulism in adults?
It involves inhibition of presynaptic acetylcholine release at the NMJ due to a preformed toxin.
What type of neurons does botulinum toxin of Clostridium botulinum target?
Motor neurons.
What type of paralysis is seen with Clostridium botulinum?
Flaccid paralysis (“botulism”).
Does cleavage of SNARE via botulinum toxin prevent release of excitatory or inhibitory neurotransmitters?
Excitatory (thus causing flaccid paralysis).
What is a potential side effect of Isoniazid?
Isoniazid can cause hepatotoxicity, which manifests as mild hepatic dysfunction or acute hepatitis.
What is the effect of being a slow acetylator on drug metabolism?
Patients who are slow acetylators have increased side effects from certain drugs due to decreased rate of metabolism.
What are the clinical presentations of DRESS syndrome?
Patients with DRESS syndrome present with fever, generalized lymphadenopathy, facial edema, and diffuse morbilliform skin rash.
What laboratory findings are associated with DRESS syndrome?
Patients with DRESS syndrome present with eosinophilia, atypical lymphocytosis, and elevated ALT.
What are common precipitating factors for DRESS syndrome?
DRESS syndrome is most commonly precipitated by allopurinol and antiepileptics (e.g. phenytoin, carbamazepine).
When does DRESS syndrome typically occur after drug exposure?
DRESS syndrome occurs 2-8 weeks after drug exposure.
Which anti-epileptic is most associated with DRESS syndrome?
Phenytoin.
Which trace mineral deficiency manifests as impaired taste, alopecia, and pustular skin rash?
Zinc deficiency
What senses are impaired with zinc deficiency?
Taste (dysgeusia) and smell (anosmia)
What mineral deficiency is associated with acrodermatitis enteropathica?
Zinc deficiency
What is a consequence of zinc deficiency?
Zinc deficiency is associated with hypogonadism
What animals are the reservoir for Yersinia pestis?
Rats, prairie dogs
How does Yersinia pestis (plague) first spread in the body?
It first spreads to the lymph nodes, forming characteristic buboes.
How is bubonic plague (Yersinia pestis) transmitted?
Fleas
What is the cause of bubonic plague?
Yersinia pestis
What is the gram stain of Yersinia?
Gram negative
What can happen to Yersinia pestis after it escapes the lymph nodes?
It can cause septicemia and widespread necrosis of the organs.
What protects Yersinia pestis from phagocytosis?
It is encapsulated.
What type of vaccine is used for Yersinia pestis?
Inactivated/Killed
What are the symptoms of serum sickness?
Serum sickness presents with fever, urticaria, arthralgia, proteinuria, and lymphadenopathy 1 - 2 weeks after antigen exposure.
What type of hypersensitivity reaction is serum sickness?
Type III HSR (immune complexes).
What is serum sickness?
Serum sickness is an immune complex disease in which antibodies to foreign serum proteins are produced.
Which reaction to monoclonal antibodies includes skin rash, fever, and arthralgias?
Serum sickness.
What are serum sickness-like reactions associated with?
Serum sickness-like reactions are associated with infections (e.g. HBV) and some drugs acting as haptens (e.g. penicillin).
What is Hirschsprung disease?
Hirschsprung disease occurs due to a congenital failure of ganglion cells to descend into the myenteric and submucosal plexus.
What do acarbose and miglitol inhibit?
Acarbose and miglitol inhibit α-glucosidase enzymes.
What is the effect of inhibiting α-glucosidase enzymes?
It decreases the conversion of disaccharides into absorbable monosaccharides.
What are examples of α-glucosidase inhibitors?
Acarbose and miglitol.
How do α-glucosidase inhibitors affect carbohydrate absorption?
They reduce the activity of α-glucosidases on the intestinal brush border, thus delaying carbohydrate hydrolysis and absorption.
What is the clinical use of α-glucosidase inhibitors?
They are used to control the postprandial glucose spike.
Why are α-glucosidase inhibitors infrequently prescribed?
Due to their ability to cause diarrhea, flatulence, and abdominal pain as side effects.
What may help in the diagnosis of cystine kidney stones?
A positive sodium cyanide nitroprusside test may help in the diagnosis of cystine kidney stones.
What is the shape of urine crystals in cystine kidney stones?
Cystine kidney stones are characterized by urine crystals that are hexagonal in shape.
Under what condition do cystine kidney stones precipitate?
Cystine kidney stones precipitate with low urine pH.
What renal disease is diagnosed by the urinary cyanide-nitroprusside test?
Cystinuria.
What is the appearance of cystine kidney stones on X-ray?
Faintly radiopaque.
What is a treatment for cystinuria?
Treatment for cystinuria includes urinary alkalinization (e.g. potassium citrate, acetazolamide).
What causes cystinuria?
Cystinuria is caused by a defect of renal PCT and intestinal amino acid transporters, preventing reabsorption of cystine, ornithine, lysine, and arginine.
In which population are cystine stones most commonly seen?
Cystine stones are a rare form of nephrolithiasis, most commonly seen in children.
What inherited pathology are cystine kidney stones associated with?
Cystinuria.
What is the appearance of cystine kidney stones on CT?
Moderately radiopaque (sometimes visible).
What does the treatment of cystine kidney stones involve?
Treatment of cystine kidney stones involves alkalinization of urine and a low-sodium diet.
What is the treatment for homocystinuria due to decreased affinity of cystathionine synthase for vitamin B6?
Very increased vitamin B6 and increased cysteine in the diet.
How is homocystinuria due to cystathionine synthase deficiency treated?
Decreased methionine and increased cysteine, B6, B12, and folate in the diet.
What enzyme converts homocysteine to cystathionine?
Cystathionine synthase (with vitamin B6 as a cofactor).
What enzyme deficiencies may cause homocystinuria?
Cystathionine synthase and methionine synthase deficiencies.
What can cause homocystinuria besides enzyme deficiencies?
Decreased affinity of cystathionine synthase for pyridoxal phosphate (B6, active form).
What is the result of cystathionine beta synthase (CBS) deficiency?
High homocysteine levels, increasing risk for thrombosis.
What are some clinical presentations of homocystinuria?
Marfanoid habitus, lens dislocation that subluxes downward and inward.
What additional symptoms may homocystinuria present with?
Intellectual disability, osteoporosis, and kyphosis.
What risks are associated with homocystinuria?
Increased risk for thrombosis and atherosclerosis, which may cause stroke and MI.
Which bacteria has gram-variable staining?
Gardnerella vaginalis
Which type of cells on wet mount signify Gardnerella vaginalis?
Clue cells
What vaginal pH is associated with Gardnerella vaginalis infection?
A vaginal pH > 4.5
What is a common presentation of Gardnerella vaginalis?
Gray discharge
What odor is associated with Gardnerella vaginalis?
Fishy smell
What is the cause of bacterial vaginosis?
Gardnerella vaginalis
Which gram-variable bacteria has a fishy odor?
Gardnerella vaginalis
Does Gardnerella vaginalis change the vaginal pH?
Yes, it does change the vaginal pH
What are risk factors for bacterial vaginosis?
Frequent vaginal douching, use of soaps with perfumes, and irritating chemicals
Which bacteria is seen sampled from the vagina?
Gardnerella vaginalis
What is the pathophysiology of bacterial vaginosis?
Decreased colonization of the vagina with lactobacilli, leading to increased pH and overgrowth of anaerobic bacteria
What test is associated with Gardnerella vaginalis?
Positive KOH whiff test
How is bacterial vaginosis diagnosed?
Diagnosis is confirmed if 3 of the Amsel criteria are met: 1) Thin-gray/white or yellow discharge 2) Vaginal pH > 4.5 3) Positive amine test (AKA ‘whiff test’) 4) Clue cells
What type of cells are classically seen in Gardnerella vaginalis?
Vaginal epithelial cells coated with bacteria
Which cause of vaginosis is non-painful?
Gardnerella vaginalis
What are schwannomas?
Schwannomas are biphasic tumors; they contain dense, hypercellular areas with spindle cells alternating with hypocellular, myxoid areas.
What do the tumor cells of a schwannoma stain positive for?
The tumor cells of a schwannoma stain positive for S-100.
What is vestibular schwannoma?
Vestibular schwannoma (acoustic neuroma) is a slow-growing tumor that typically arises from Schwann cells in the vestibular nerve.
Where are vestibular schwannomas typically located?
Vestibular schwannomas are typically located on CN VIII in the internal acoustic meatus.
Can vestibular schwannomas extend outside the internal acoustic meatus?
Yes, vestibular schwannomas may extend outside the internal acoustic meatus to the cerebellopontine angle.
What is used to diagnose vestibular schwannoma?
MRI of the internal auditory canals is used to diagnose vestibular schwannoma (acoustic neuroma).
What is Lynch syndrome?
Lynch syndrome is due to an inherited defect in DNA mismatch repair enzymes, resulting in microsatellite instability.
What is the mode of inheritance of Lynch syndrome?
Autosomal dominant.
What cancers are associated with Lynch syndrome?
Increased risk for colorectal, endometrial, ovarian, and gastric cancers.
Where does Lynch syndrome usually occur in the colon?
Lynch syndrome is usually right-sided and always involves the proximal colon.
How do Lynch syndrome and some sporadic colorectal carcinomas arise?
They arise via the microsatellite instability pathway.
What pathology is characterized by a deficiency of the enzymes used in mismatch base repair?
Lynch syndrome.
What percentage of Lynch syndrome patients progress to colorectal carcinoma?
~ 80% of patients.
What was Lynch syndrome previously known as?
Hereditary nonpolyposis colorectal cancer (HNPCC).
What is spina bifida due to?
Spina bifida is due to failure of the posterior vertebral arch to close.
Which form of spina bifida is associated with herniation of meninges (but no neural tissue) through the bony defect?
Meningocele.
Which form of spina bifida is associated with a tuft of hair or skin dimple at the level of the bone defect?
Spina bifida occulta.
Which form of spina bifida is associated with herniation of meninges and neural tissue through the bony defect?
Myelomeningocele.
What pathology is associated with disruption of the caudal end of the neural tube?
Spina bifida.
Which form of spina bifida is associated with failure of the bony spinal canal to close but with no herniation?
Spina bifida occulta.
How are open neural tube defects detected during prenatal care?
Open neural tube defects are detected by elevated alpha-fetoprotein (AFP) levels in the amniotic fluid and maternal blood.
What characterizes spina bifida occulta in terms of AFP levels?
Spina bifida occulta is characterized by normal levels of AFP in utero.
Is the dura intact in spina bifida occulta?
Yes.
What malformation is often associated with lumbosacral myelomeningocele?
Chiari II malformation.
Where is spina bifida occulta usually seen?
Spina bifida occulta is usually seen at lower vertebral levels.
What malformation is associated with non-communicating hydrocephalus and spina bifida?
Dandy-Walker malformation.
What is the cause of esophageal dysmotility in CREST syndrome?
Fibrous replacement of the muscularis in the lower esophagus.
What does ‘CREST syndrome’ stand for?
Calcinosis cutis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, Telangiectasias.
Which type of scleroderma is associated with the anti-centromere antibody?
Limited scleroderma (CREST syndrome).
What predisposes to acid reflux and dysphagia in scleroderma?
Low LES pressure.
What characterizes sclerodermal esophageal dysmotility?
Low LES pressure on esophageal manometry.
What is silicosis?
Silicosis is a pneumoconiosis that results from prolonged silica exposure.
What are the characteristic features of silicosis?
Silicosis presents with fibrotic nodules in the upper lobes of the lung.
What calcification may be observed in silicosis?
Silicosis may present with ‘eggshell’ calcification of the hilar lymph nodes.
Which pneumoconiosis has an increased risk for tuberculosis (TB)?
Silicosis has an increased risk for tuberculosis (TB).
In which occupations is silicosis commonly seen?
Silicosis is seen in sandblasters, miners (silica/coal), and foundry workers.
What is myeloperoxidase deficiency associated with?
Increased risk for Candida infection; however, most patients are asymptomatic.
What is intact in myeloperoxidase (MPO) deficiency?
The respiratory burst, which produces superoxide (O2-) and hydrogen peroxide (H2O2).
Which immunodeficiency is characterized by the inability to generate HClO (hypochlorite) from H2O2?
Myeloperoxidase deficiency.
What type of receptor does Glycopyrrolate antagonize?
Glycopyrrolate is an M3 receptor antagonist.
What effect do antimuscarinics have on sweat glands?
Antimuscarinics cause hyperthermia due to inhibition of sweat glands.
What neurotransmitter is released by postganglionic sympathetic fibers in sweat glands?
Post-ganglionic sympathetic neurons utilize acetylcholine as a neurotransmitter in sweat glands.
What is one adverse effect of antimuscarinics?
One adverse effect of antimuscarinics is dry, flushed skin.
Which neurotransmitter’s release is prevented by the botulinum toxin from Clostridium botulinum?
Acetylcholine.
What may occur if dextromethorphan is combined with other serotonergic agents?
Dextromethorphan may cause serotonin syndrome.
What type of drug is dextromethorphan?
Dextromethorphan is an antitussive.
How does dextromethorphan exert its effects?
It exerts its effects via antagonism of NMDA glutamate receptors and stimulation of sigma receptors.
What is homocystinuria?
Homocystinuria is a metabolic disorder characterized by excess homocysteine.
What are the risks associated with homocystinuria?
Homocystinuria causes increased risk for thrombosis and atherosclerosis, which may cause stroke and myocardial infarction (MI).
What are the clinical presentations of homocystinuria?
Homocystinuria may present with marfanoid habitus, lens dislocation that subluxes downward and inward, intellectual disability, osteoporosis, and kyphosis.
What enzyme deficiencies may cause homocystinuria?
Cystathionine synthase and methionine synthase deficiencies.
What is the mode of inheritance of homocystinuria?
Autosomal recessive.
How is homocystinuria due to methionine synthase deficiency treated?
It is treated with increased methionine in the diet.
How is homocystinuria due to decreased affinity of cystathionine synthase for vitamin B6 treated?
It is treated with very increased vitamin B6 and increased cysteine in the diet.
What does cystathionine beta synthase (CBS) deficiency result in?
CBS deficiency results in high homocysteine levels, increasing risk for thrombosis.
What additional cause can lead to homocystinuria?
Homocystinuria may also be caused by decreased affinity of cystathionine synthase for pyridoxal phosphate (B6, active form).
How is homocystinuria due to cystathionine synthase deficiency treated?
It is treated with decreased methionine and increased cysteine, vitamin B6, vitamin B12, and folate in the diet.
What is mycosis fungoides?
Mycosis fungoides is a neoplastic proliferation of mature CD4+ T cells.
How may mycosis fungoides spread?
Mycosis fungoides may spread to involve the blood, producing Sézary syndrome (T-cell leukemia).
What characterizes Sézary syndrome?
Sézary syndrome is characterized by atypical CD4+ T cells with cerebriform nuclei seen on blood smear.
What are Pautrier microabscesses?
The aggregates of neoplastic cells in the epidermis seen with mycosis fungoides are called Pautrier microabscesses.
What is the diagnosis for pruritic cutaneous plaques and patches that develop brownish nodules?
Mycosis fungoides.
How does mycosis fungoides typically present?
Mycosis fungoides typically presents in adults with skin patches/plaques.
Is pancreatic insufficiency associated with normal or decreased urinary excretion of D-xylose?
Normal
What does the D-xylose absorption test help distinguish?
It helps distinguish GI mucosal damage from other causes of malabsorption (e.g. lactose intolerance, pancreatic insufficiency)
What condition may present with pancreatic insufficiency?
Chronic pancreatitis
What are the consequences of pancreatic insufficiency?
It results in malabsorption with steatorrhea and fat-soluble vitamin deficiencies
What does pancreatic insufficiency cause malabsorption of?
It causes malabsorption of fat, fat-soluble vitamins, and vitamin B12
What are the three major approaches to treatment of chronic pancreatitis?
- Pain management 2. Pancreatic enzyme supplementation 3. Tobacco and alcohol cessation
What is B-ALL characterized by?
B-ALL is usually characterized by lymphoblasts (TdT+) that express CD10, CD19, and CD20.
What is T-ALL characterized by?
T-ALL is characterized by lymphoblasts (TdT+) that express markers ranging from CD2 to CD8.
What symptoms in a child suggest acute lymphoblastic leukemia?
Bruising, petechiae, bleeding, non-tender lymphadenopathy, and hepatosplenomegaly.
Which type of ALL is the most common?
B-ALL.
How is acute lymphoblastic leukemia subclassified?
Acute lymphoblastic leukemia is subclassified into B-ALL and T-ALL based on surface markers.
What is the diagnosis in a young patient with anterior cervical lymphadenopathy, hepatosplenomegaly, and bruising?
Acute lymphoblastic leukemia.
What causes T-cell ALL?
T-cell ALL is caused by a mutation in a pre-T-cell in the thymus.
What causes B-cell ALL?
B-cell ALL is caused by a mutation in a pre-B-cell in the bone marrow.
What is T-ALL characterized by?
T-ALL is characterized by lymphoblasts (TdT+) that express markers ranging from CD2 to CD8.
In which age group does T-ALL usually present?
T-ALL usually presents in teenagers as a mediastinal mass, thus it is often referred to as acute lymphoblastic lymphoma.
What is the diagnosis in a young patient with anterior cervical lymphadenopathy, hepatosplenomegaly, and bruising?
Acute lymphoblastic leukemia.
What symptoms may T-cell ALL present with?
T-cell ALL may present with SVC syndrome, stridor, dysphagia, or dyspnea.
What is the likely diagnosis in a child with bone pain, non-tender lymphadenopathy, and pancytopenia?
Acute lymphoblastic leukemia.
Where does T-cell ALL often present with lymphadenopathy?
T-cell ALL often presents with lymphadenopathy, particularly in the cervical, supraclavicular, and axillary lymph nodes.
What symptoms in a child suggest acute lymphoblastic leukemia?
Bruising, petechiae, bleeding, non-tender lymphadenopathy, and hepatosplenomegaly.
How may acute lymphoblastic leukemia present due to leukemic cell infiltration?
Acute lymphoblastic leukemia may present with hepatosplenomegaly and lymphadenopathy.
What causes T-cell ALL?
T-cell ALL is caused by a mutation in a pre-T-cell in the thymus.
What causes B-cell ALL?
B-cell ALL is caused by a mutation in a pre-B-cell in the bone marrow.
What is ALL?
ALL is a neoplastic accumulation of lymphoblasts (> 20%) in the bone marrow.
What are common presentations of acute lymphoblastic leukemia in children?
Acute lymphoblastic leukemia is a childhood cancer that may present with bruising, petechiae, and mucosal bleeding due to thrombocytopenia.
What is primary membranous nephropathy associated with?
Autoantibodies against the transmembrane phospholipase A2 receptor found in high concentrations in glomerular podocytes.
What characterizes membranous nephropathy on electron microscopy?
Subepithelial deposits with a ‘spike and dome’ appearance.
What causes the ‘spike’ appearance in membranous nephropathy?
The basement membrane engulfing ‘domes’ of subepithelial immune deposits.
What is a ‘membranous’ glomerular disorder characterized by?
Thickening of the glomerular basement membrane.
What immunofluorescence findings are associated with membranous nephropathy?
Granular deposits (immune complex deposition).
What type of nephrotic syndrome are SLE patients most likely to get?
Membranous nephropathy.
What does membranous nephropathy show on light microscopy?
Diffuse capillary and GBM thickening.
Which type of nephrotic syndrome is commonly seen secondary to solid tumors?
Membranous nephropathy.
Which type of nephrotic syndrome is most commonly associated with renal vein thrombosis?
Membranous nephropathy.
What is nephrotic syndrome characterized by?
Proteinuria > 3.5 g/day.
What is the most common cause of nephrotic syndrome in White adults?
Membranous nephropathy.
What induces ICAM-1 and VCAM-1 expression?
ICAM-1 and VCAM-1 expression are induced by TNF-α and IL-1.
What are ICAM-1 and VCAM-1?
ICAM-1 and VCAM-1 are cellular adhesion molecules that are upregulated on endothelium during leukocyte adhesion.
What induces E-selectin expression?
E-selectin expression is induced by IL-1 and TNF.
What is the role of cellular adhesion molecules (CAMs)?
Cellular adhesion molecules (CAMs) on endothelial cells bind integrins on leukocytes, resulting in firm adhesion to the vessel wall.
What two steps of leukocyte extravasation occur directly after adhesion?
Transmigration and chemotaxis.
What step of leukocyte extravasation occurs directly after rolling?
Adhesion.
What mnemonic helps remember the characteristics of tuberous sclerosis?
HAMAARTOMAS
What are Ash-leaf spots?
Hypopigmented macules associated with tuberous sclerosis.
What does the TSC1 gene encode and where is it located?
The TSC1 gene encodes for hamartin and is located on chromosome 9.
What does the TSC2 gene encode and where is it located?
The TSC2 gene encodes for tuberin and is located on chromosome 16.
What are Angiofibromas?
Also known as adenoma sebaceum, they are a feature of tuberous sclerosis.
What are Shagreen patches?
Patches of localized leathery thickenings associated with tuberous sclerosis.
What type of tumor is associated with tuberous sclerosis?
Cardiac rhabdomyoma.
What is the mode of inheritance of tuberous sclerosis?
Autosomal dominant.
What are glioneuronal hamartomas also known as?
Cortical tubers, most common in the cerebral cortex.
What are subependymal nodules?
CNS hamartomas that line the ventricular system.
What astrocyte-derived CNS tumor is associated with tuberous sclerosis?
Subependymal giant cell astrocytomas (SEGA).
What complication can CNS hamartomas cause in tuberous sclerosis?
Non-communicating (obstructive) hydrocephalus due to CSF blockage.
What is the increased frequency of renal angiomyolipoma associated with?
Patients with tuberous sclerosis.
What is seborrheic keratosis characterized by histologically?
Seborrheic keratosis is characterized histologically by keratin pseudocysts (horn cysts).
Which skin disorder can present as a raised, discolored plaque with a waxy, ‘stuck on’ appearance?
Seborrheic keratosis.
What type of neoplasms are seborrheic keratoses?
Seborrheic keratoses are benign squamous neoplasms.
Where are seborrheic keratoses typically seen?
Seborrheic keratoses are typically seen on the head, trunk, and extremities in the elderly.
What is osteochondroma?
Osteochondroma is a benign bone tumor with an overlying cartilage cap.
Where does osteochondroma arise?
Osteochondroma arises as a lateral projection of the growth plate (metaphysis).
What is the most common benign tumor of bone?
Osteochondroma.
How does osteochondroma grow?
Osteochondroma is a slow growing bone tumor commonly found at the distal femur (near the knee).
Are osteochondromas usually painful?
Osteochondromas are usually painless.
What demographic is associated with osteochondroma?
Males < 25 years old.
Can the cartilage in osteochondroma transform?
The overlying cartilage in osteochondroma rarely transforms to chondrosarcoma.
What is craniopharyngioma?
Craniopharyngioma is a benign tumor of Rathke pouch that is filled with cholesterol crystals and calcifications.
What is the likely diagnosis in a child that presents with bitemporal hemianopsia and diabetes insipidus with calcified pituitary mass on imaging?
Craniopharyngioma.
Which CNS tumor compresses the optic chiasm, causing bitemporal hemianopsia, in children?
Craniopharyngioma.
Which CNS tumor is characterized by cholesterol crystals found in ‘motor-oil’-like fluid within the tumor?
Craniopharyngioma.
What is the origin of craniopharyngioma?
Craniopharyngioma arises from epithelial remnants of the Rathke pouch (oral ectoderm).
What complications can arise from craniopharyngioma?
A craniopharyngioma may cause pressure necrosis and lead to hypopituitarism.
What is struma ovarii?
Struma ovarii is a cystic teratoma composed primarily of thyroid tissue.
What condition may struma ovarii cause?
Struma ovarii may cause hyperthyroidism.
What mnemonic helps remember the drugs for malaria prophylaxis in chloroquine-resistant regions?
MAD Travellers
What does ‘M’ stand for in the mnemonic ‘MAD Travellers’?
Mefloquine-SAFE IN PREGNANCY
What does ‘A’ stand for in the mnemonic ‘MAD Travellers’?
Atovaquone-proguanil
What does ‘D’ stand for in the mnemonic ‘MAD Travellers’?
Doxycycline
What does ‘T’ stand for in the mnemonic ‘MAD Travellers’?
Tafenoquine
What is oral isotretinoin used to treat?
Oral isotretinoin is used to treat severe cystic acne.
What are retinoids?
Retinoids are derivatives of vitamin A.
What does the t(15;17) translocation result in?
The t(15;17) translocation results in disruption of the retinoic acid receptor on chromosome 17.
How is acute promyelocytic leukemia treated?
Acute promyelocytic leukemia is treated with all-trans-retinoic acid (ATRA) and arsenic trioxide.
What does all-trans-retinoic acid (ATRA) do in acute promyelocytic leukemia?
All-trans-retinoic acid (ATRA) binds the altered retinoic acid receptor in acute promyelocytic leukemia and causes blasts to mature.
What significant laboratory finding is associated with granulomatosis with polyangiitis (GPA)?
Positive c-ANCA
Which cause of pauci-immune glomerulonephritis is associated with c-ANCA (PR3-ANCA)?
Granulomatosis with polyangiitis (GPA)
What is granulomatosis with polyangiitis (GPA)?
A form of necrotizing, granulomatous vasculitis that classically involves the nasopharynx, lungs, and kidneys.
Which vasculitis is characterized by a triad of: (1) Focal necrotizing vasculitis (2) Necrotizing granulomas in the lung and upper airway (3) Necrotizing glomerulonephritis?
Granulomatosis with polyangiitis (GPA)
What is the likely diagnosis in a patient with sinusitis/otalgia, lung nodules/cavitations, and elevated creatinine/hematuria?
Granulomatosis with polyangiitis (GPA)
What does a chest X-ray of a patient with granulomatosis with polyangiitis (GPA) show?
Bilateral large nodular densities/infiltrates
What kidney-related symptoms are often presented in granulomatosis with polyangiitis (GPA)?
Hematuria, red cell casts, and rapidly progressive glomerulonephritis (RPGN)
What lower respiratory tract symptoms are often presented in granulomatosis with polyangiitis (GPA)?
Hemoptysis, cough, and dyspnea
What are serum sickness-like reactions associated with?
Serum sickness-like reactions are associated with infections (e.g. HBV) and some drugs acting as haptens (e.g. penicillin).
What are the symptoms of serum sickness?
Serum sickness presents with fever, urticaria, arthralgia, proteinuria, and lymphadenopathy 1 - 2 weeks after antigen exposure.
What drug classes are most commonly associated with serum sickness-like reactions?
β-lactams and sulfa drugs.
How can Hepatitis B virus present similarly to serum sickness?
Hepatitis B virus can present similar to serum sickness, with fever, rash, and arthralgias.
What are the associated toxicities of isoniazid (INH) use?
Hepatotoxicity and neurotoxicity.
How does isoniazid (INH) work?
It inhibits the synthesis of mycolic acid by Mycobacterium tuberculosis.
What effect does isoniazid have on cytochrome P450?
Isoniazid inhibits cytochrome P450.
What vitamin deficiency is caused by isoniazid and what is its consequence?
Isoniazid promotes the excretion of pyridoxine (vitamin B6), resulting in deficiency and peripheral neuropathy.
What liver function test result indicates hepatotoxicity from isoniazid?
An asymptomatic rise in aminotransferases (AST, ALT).
What is an immunologic toxicity associated with isoniazid use?
Drug-induced lupus.
What condition can result from B6 depletion due to isoniazid?
Sideroblastic anemia due to decreased δ-aminolevulinic acid synthesis.
What are common side effects of isoniazid therapy?
Peripheral neuropathy, ataxia, and paresthesias.
When can isoniazid be given as monotherapy for tuberculosis?
Only when there is a positive PPD and a negative chest x-ray.
Who has an increased risk of side effects from isoniazid?
Slow-acetylators.
What activates isoniazid (INH)?
It is activated by KatG (a catalase-peroxidase) produced by Mycobacterium tuberculosis.
What CNS effects can isoniazid cause?
Altered mental status and seizures.
What virus causes myocarditis that progresses to dilated cardiomyopathy?
Coxsackie B
What cardiac pathology can be caused by adenovirus, coxsackie B, parvovirus B19, HIV, and roseola (HHV-6/7)?
Myocarditis
What is the likely diagnosis in a child that presents with fever and signs of heart failure after several days of a URI?
Viral myocarditis
What characterizes myocarditis secondary to coxsackie B infection?
Lymphocytic infiltrate in the myocardium
What is highly indicative of viral myocarditis on biopsy?
Lymphocytic infiltrate with focal necrosis
What is the likely diagnosis in a young adult with a month-long history of fever and malaise that develops symptoms of CHF with cardiomegaly on imaging?
Viral myocarditis
What cardiac complication do Kawasaki disease, sarcoidosis, SLE, and poly/dermatomyositis share?
Myocarditis
What are the complications of myocarditis?
Arrhythmias, heart failure, cardiogenic shock, and dilated cardiomyopathy
What cardiac pathology results in inflammation with global enlargement, 4-chamber dilation, and diffuse hypokinesis?
Myocarditis
What are spherocytes?
Spherocytes are pathologic RBCs that have an increased mean corpuscular hemoglobin concentration (MCHC).
What is hereditary spherocytosis characterized by?
Hereditary spherocytosis is characterized by an increased RDW.
What finding emerges on blood smear following splenectomy in a patient with hereditary spherocytosis?
Howell-Jolly bodies.
What type of hemolysis is primarily associated with hereditary spherocytosis?
Hereditary spherocytosis is primarily characterized by extravascular hemolysis.
How is hereditary spherocytosis inherited?
Hereditary spherocytosis is most often inherited in an autosomal dominant pattern.
What causes RBCs to become round (spherocytes) in hereditary spherocytosis?
Loss of membrane blebs in hereditary spherocytosis renders RBCs round instead of disc-shaped.
What is the underlying defect in hereditary spherocytosis?
Hereditary spherocytosis is due to an inherited defect of RBC cytoskeleton-membrane tethering proteins.
What test demonstrates increased spherocyte fragility in hereditary spherocytosis?
Hereditary spherocytosis demonstrates increased spherocyte fragility in hypotonic solution (osmotic fragility test).
What RBC pathology is characterized by formation and loss of membrane blebs over time?
Hereditary spherocytosis.
What does the eosin-5-maleimide (EMA) binding test show in hereditary spherocytosis?
Hereditary spherocytosis will show decreased mean fluorescence of RBCs in the EMA binding test.
What is associated with normocytic anemia and extravascular hemolysis?
Normocytic anemia with extravascular hemolysis is associated with enlargement of the spleen (splenomegaly).
Do spherocytes persist following splenectomy in hereditary spherocytosis?
Yes.
What is the risk associated with normocytic anemia and extravascular hemolysis?
Normocytic anemia with extravascular hemolysis is associated with increased risk for bilirubin gallstones.
What causes jaundice in normocytic anemia with extravascular hemolysis?
Jaundice is due to increased serum unconjugated bilirubin.
What type of anemia is hereditary spherocytosis a cause of?
Hereditary spherocytosis is a cause of microcytic or normocytic anemia.
What is a phyllodes tumor?
A fibroadenoma-like tumor with overgrowth of the fibrous component, causing ‘leaf-like’ projections.
Which two breast pathologies affect the stroma of the breast tissue?
Fibroadenoma and phyllodes tumor.
What causes exudative pleural effusion?
Exudative pleural effusion is caused by states of increased vascular permeability (e.g., malignancy, pneumonia, trauma, collagen vascular disease).
What is the pleural/serum LDH ratio for exudative pleural effusions?
Exudative pleural effusions are characterized by pleural/serum LDH ratio > 0.6 (high).
What is the pleural/serum LDH ratio for transudative pleural effusions?
Transudative pleural effusions are characterized by pleural/serum LDH ratio < 0.6 (low).
How is exudate characterized in terms of LDH?
Exudate is characterized by increased LDH compared to serum.
What are Light’s criteria for exudative pleural effusions?
Exudative pleural effusions must meet one of Light’s criteria: Pleural protein/serum protein > 0.5, Pleural LDH/serum LDH > 0.6, or Pleural LDH > 2/3 upper limit of normal serum LDH.
What distinguishes types of pleural effusions?
Types of Pleural Effusions: Exudate = ↑ LDH/proteins/lipids; Transudate = ↓ LDH/proteins/lipids.
What is the protein content characteristic of exudative pleural effusion?
Exudative pleural effusion is characterized by high protein content.
What is the pleural/serum protein ratio for exudative pleural effusions?
Exudative pleural effusions are characterized by a pleural/serum protein ratio > 0.5 (high).
What is myocarditis secondary to rheumatic fever associated with?
Myocarditis secondary to rheumatic fever is associated with Aschoff bodies, which are granulomas with giant cells and fibrinoid material.
What are Anitschkow cells?
Anitschkow cells are reactive histiocytes with slender, wavy nuclei.
What is Langerhans cell histiocytosis characterized by?
Birbeck (tennis racket) granules on electron microscopy.
What stain can be used to identify melanomas, schwannomas, and Langerhans cell histiocytosis?
S-100 stain.
How may Langerhans cell histiocytosis present clinically?
As recurrent otitis media with a mass involving the mastoid bone.
In which population is Langerhans cell histiocytosis most common?
In children.
What symptoms does Langerhans cell histiocytosis cause?
Symptoms in the bone and skin.
What markers are Langerhans cells positive for on immunohistochemistry?
CD1a and S-100.
Which form of Langerhans cell histiocytosis presents as scalp rash, lytic skull lesions, diabetes insipidus, and exophthalmos?
Hand-Schüller-Christian disease.
What type of proliferation is Langerhans cell histiocytosis?
A neoplastic proliferation of Langerhans cells.
From where are Langerhans cells derived?
From bone marrow monocytes.
Do the Langerhans cells in Langerhans cell histiocytosis effectively stimulate primary T cells via antigen presentation?
No, they are functionally immature.
What does hCG indicate in relation to thyroid function?
hCG is associated with increased thyroid function.
In which conditions is β-hCG elevated?
β-hCG is elevated in gestational trophoblastic disease (GTD), testicular cancer (non-seminomatous), and mixed germ cell tumors.
What effects can elevated hCG levels cause?
Elevated hCG levels may cause precocious puberty, gynecomastia in males, or hyperthyroidism.
Why can hCG cause hyperthyroidism?
hCG can cause hyperthyroidism due to its homology with FSH, LH, and TSH.
What family of hormones is hCG structurally related to?
hCG is structurally related to the TSH, FSH, and LH family.
What is identical among the hormones TSH, LH, FSH, and hCG?
The α subunits of TSH, LH, FSH, and hCG are identical.
What is the appearance of uric acid kidney stones on X-ray?
Radiolucent
What type of kidney stone is seen in patients with gout?
Uric acid stone
What is the treatment for uric acid kidney stones?
Alkalinization of urine
What urine condition precipitates uric acid kidney stones?
Low urine pH
What may trigger acute gout related to uric acid?
Alcohol consumption due to competition for excretion in the kidney
How can chronic diarrhea affect uric acid kidney stones?
Increases H+ excretion, leading to metabolic acidosis
What additional treatments may be used for uric acid kidney stones?
IV hydration and a low-purine diet, potassium citrate
What imaging modality may be used to visualize uric acid kidney stones?
Ultrasound
Which gout drug can result in uric acid kidney stones?
Probenecid
How does Probenecid affect uric acid excretion?
Increases uric acid excretion, thus increasing the risk of uric acid kidney stones
What medication may be included in the treatment of uric acid kidney stones for gout patients?
Allopurinol
What can precipitate gout related to hydration status?
Dehydration due to hypovolemia and increased uric acid concentration
What renal condition may lead to secondary gout?
Renal insufficiency due to decreased ability to excrete uric acid
What can chronic gout lead to regarding kidney health?
Renal failure due to deposition of urate crystals in kidney tubules
What is the prevalence of uric acid stones among kidney stones?
Third most common type (5%)
What accounts for 50% of uric acid kidney stones?
Idiopathic acidic urine
In what conditions are uric acid kidney stones often seen?
Diseases with increased cell turnover (e.g. leukemia, myeloproliferative disorders)
What are risk factors for uric acid kidney stones?
Hot/arid climates and low urine volume
What can be used for prophylaxis of uric acid stones?
Xanthine oxidase inhibitors
What is cachexia mediated by?
Pro-inflammatory cytokines (TNF, IFN-γ, IL-1, and IL-6)
These cytokines activate the ubiquitin-proteasome pathway.
What role does TNF-α play in the body?
It is a cytokine released from macrophages that mediates cachexia and shock
TNF-α is implicated in inflammatory responses.
