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USMLE Step 1 Prep > First Aid: Endocrine > Flashcards

First Aid: Endocrine Flashcards

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1
Q

What is the most common site for ectopic thyroid tissue?

A

Tongue

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2
Q

A patient presents with an anterior midline neck mass that moves with swallowing or protrusion of the tongue. What may this be?

A

Thyroglossal duct cyst

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3
Q

What is the most commons tumor of the adrenal medulla in adults and what would a patient present with?

In children?

A

Adults = Pheochromocytoma; Episodic HTN

Children = Neuroblastoma; rarely causes HTN

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4
Q

What are the layers of the adrenal cortex and how are they regulated? What secretory products does each layer release?

A

GFR - Zona Glmoerulosa (Renin-angiotensin), Fasiculata (ACTH,CRH), Reticularis (Acth, CRH)

“The deeper you go the sweeter it gets”
Salt (Na+) –> Sugar (glucocorticoids) –> Sex (androgens)

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5
Q

What is the adrenal medulla composed of and what does it release? How could you inhibit regulation of this structure?

A

Chromaffin Cells (derived from neural crest)

Release Catecholamines (Epi, NE)

Inhibit SANS would block preganglionic sympathetic fibers

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6
Q

What are the main differences between the posterior pituitary (neurohypophysis) and the anterior pituitary (adenohypophysis)?

A

Post Pit is from neuroectoderm and secretes vasopressin and oxytocin

Ant Pit is from oral ectoderm (rathke pouch) and secretes FSH, LH, ACTH, TSH, Prolactin, GH, melanotropin (MSH)

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7
Q

What three hormones are secreted from the endocrine pancreas and what are responsible for releasing them?

A
  1. Glucagon - from alpha cells, (afar on the outside)
  2. Insulin - from beta cells (inside)
  3. Somatostatin - from gamma cells (dispersed)
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8
Q

What is increased in an insulinoma?

A

C-peptide and Insulin

Exogenous insulin lacks C-Peptide

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9
Q

Which structures have insulin-INdependent glucose uptake?

A

BRICK L

Brain, RBCs, Intestine, Cornea, Kidney, Liver

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10
Q

What are the three main compounds that will increase insulin and what are the perils of some of these effects?

A
  1. Glucose (too much –> insulin resistance)
  2. Growth Hormone (ditto)
  3. beta2-agonists
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11
Q

What are three ways of inhibiting glucagon? Which of these also inhibit insulin release?

A
  1. INsulin
  2. Hyperglycemia
  3. Somatostatin (also inhibits insulin)
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12
Q

Analogs of what hormone can be used to treat acromegaly, and why?

A

Somatostatin because it decreases GH and TSH

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13
Q

What are the varying effects on the body based on different modes of GnRH secretion?

What would occur in a patient with pituitary prolactinoma?

A

Tonic GnRH suppresses HPA axis
Pulsatile GnRH leads to puberty and fertility

Prolactin decreases GnRH, in excess (symptoms of menopause!!) –> amenorrhea, osteoporosis, decreased libido

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14
Q

How may a prolactinoma be treated and why? What would be devastating drugs or conditions to give someone with this disorder?

A

Tx: Dopamine agonists (bromocriptine) b/c dop inhibits prolactin secretion

Do not give Dopamine antagonists (most antipsychotics) and estrogens (OCPs, pregnancy) as these will STIMULATE prolactin secreation

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15
Q

What regulates Growth Hormone Secretion?

A

Increase during exercise and sleep

Decrease from glucose and somatostatin

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16
Q

What happens to ADH levels during central diabetes insipidus and how may you treat this? What about nephrogenic DI?

A

Decrease in Central DI
Tx: Desmopressin (ADh analog)

Increase in nephrogenic DI b/c of mutation in V2 receptor

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17
Q

A patient presents with HTN, hypokalemia and decreased DHT. They are XY pseudo-hermaphrodite with ambiguous genitalia and undescended testes. Aldosterone is increased while androgens and cortisol are decreased. What is their deficiency?

A

17 alpha-hydroxylase - mineralocorticoids are bypassed but glucocorticoids and sex hormones are shunted off

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18
Q

An infant presents with hypotension, hyperkalemia and salt wasting. Aldosterone and cortisol are low, but sex hormones are normal. What deficiency is this and what compound will be elevated? How else could they present?

A

21-Hydroxylase deficiency - sex hormones normal but Cortisol and Aldosterone formation is shunted off (HYPOALDOSTERONE). 17-Hydroxy-progesterone will be elevated.

May present in childhood with precocious puberty or XX:virilization

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19
Q

A young female presents with secondary male characteristics from virilization. She also has HTN and decreased aldosterone and cortisol levels. Androgen is increased. What caused the increase in blood pressure?

A

11 beta-hydroxylase deficiency

elevated 11-deoxycorticosterone causes an elevated BP with low-renin

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20
Q

What are the six main features of increased cortisol? And what will cause prolonged secretion of cortisol?

A

Chronic stress leads to excess –> BIG FIB

Blood pressure INCR
Insulin resistance INCR
Gluconeogenesis, lipolysis, proteolysis INCR

Fibroblast activity DECR
Inflammatory/Immune response DECR
Bone formation DECR

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21
Q

A patient presents with increased serum Ca, decreased serum phosphate and increased urine phosphate. What may be elevated in this patient and what does this compound cause in excess?

A

Parathyroid Hormone

INCR bone resorption of Ca and PO4
INCR kidney reabsorption of Ca in DCT
INCR calcitriol production (kidney 1alpha-hydroxylase)
DECR reabsorption of PO4 in PCT

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22
Q

A patient presents with cramps, pain, paresthesias and carpopedal spasm. Their serum pH is elevated. WHat may be the cause for this?

A

Hypocalcemia from increased Ca binding to albumin

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23
Q

What compound could lower free testosterone leading to gynecomastia in a man? What effect would low levels of this compound have on women?

A

Increase in Sex Hormone-Binding Globulin (SHBG)

Hirsituism in female if decreased

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24
Q

What are the four functions of T3?

A

4 B’s, Brain maturation, Bone growth, Beta-adrenergic effects, Basal metabolic rate increase

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25
Q

Where do antithyroid drugs target to treat hyperthyroidism?

A

Propylthiouracil inhibits both peroxidase and 5’deiodinase

Methimazole inhibits peroxidase only

Both inhibit MIT/DIT coupling in lumen of thyroid

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26
Q

A 43 year old man presents with decreased libido and a headache. On further examination you find he has bitemporal heminopsia. What are the two major next steps in care you must take?

A

Prolactinoma

  1. Bromocriptine (Dop Agonist) to shrink the tumor
  2. Surgery if needed
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27
Q

A 37 year old woman presents with cardiac problems and eventually expires from heart failure. On autopsy you notice an enlarged tongue, large hands and feet, and coarse facial features. You also find an enlarged heart and a pituitary adenoma. If you were able to take a serum sample what 3 key findings would you encounter? Say you were able to save the patient and resect the tumor, but symptoms persisted, what treatment would you use next?

A

Elevated 1. Growth Hormone, 2. IGF1, 3. Glucose

Tx: Octreotide (Somatostatin analog - blocks release of GHRH) or pegvisomant (growth hormone receptor antagonist)

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28
Q

A 28 year old woman is seen postpartum, complaining of inability to lactate. She had a complicated birth which involved C-section and increased blood loss. On physical exam you notice loss of pubic hair. What caused this problem and how can you treat it?

A

Sheehan Syndrome - pituitary gland size increased during pregnancy, blood supply cannot match –> infarction –> decreased release of sex hormones

Tx: Hormone replacement therapy

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29
Q

A 5 year old is seen following neurological surgery, complaining of intense thirst and polyuria. Urine specific gravity is 290 mOsm/L. What is the cause for his symptoms and what test would you do next? How would you treat?

A

Central Diabetes Insipidus, probably from surgery
Decrease in ADH causes sx

Water restriction test and if you have >50% increase in urine osmolarity, it confirms

Tx: Desmopressin (ADH analog)

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30
Q

A 23 year old female patient with bipolar depression presents complaining of polydypsia and polyuria. Urine specific gravity is 290 mOsm/L. They are currently on lithium medication. What may be the cause of this condition and how can you confirm? ADH levels? Treatment?

A

Nephrogenic Diabetes INsipidus, secondary to Lithium (ADH antagonist)

Water restriction test –> No change in urine osmolarity
ADH levels are normal

Tx: Stop medication, Amiloride, indomethacin and/or hydration

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31
Q

A 34 year old patient presents with mental status changes and a recent seizure. He is found to have cerebral edema. He is hyponatremic and has a urine osmolarity > serum osmolarity. Aldosterone levels are also decreased. How would you approach the treatment of this patient and what special precautions do you want to take?

A

Tx for SIADH fluid restriction, IV hypertonic saline, conivaptan, tolvaptan, demeclocycline

Correct slowly to prevent central pontine myelinolysis

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32
Q

What are the possible causes for SIADH?

A
  1. Ectopic ADH secretion (small cell lung carcinoma)
  2. CNS disorder/head trauma
  3. Pulmonary disease (infection, COPD etc.)
  4. Drugs (e.g. cyclophosphamide)
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33
Q

What effects does hyperthyroidism have on Basal Metabolic Rate and sympathetic nervous activity, and what leads to these changes?

A

Increase in BMR from increased Na/K ATPase activity

Increase in SANS from increased beta1-adrenergic receptor activity

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34
Q

A patient presents with weight loss and increased appetite, elevated heart rate, chest pain, arrhythmia, tremor and difficulty going to sleep. He also complains that he is unable to do daily physical activity because of muscle weakness and heat intolerance. He also complains of diarrhea. On physical exam you notice warm, moist skin, periorbital edema, and fine hair. The activity of which proteins is increased leading to these changes? What hormones would be elevated? Decreased?

A

Hyperthyroidism - increased Na/K ATPase and beta-1-adrenergic receptor activity

Increased free/total T3/T4 and

Decreased TSH (if this is primary hyperthyroidism)

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35
Q

What are two very characteristic biochemical changes that are correlated with hyperthyroidism?

A

Hypocholesterolemia and Hyperglycemia (from increased gluconeogenesis and glycogenolysis)

36
Q

A 26 year old anxious appearing woman presents after giving birth with exopthalmos, pretibial myxedema, and diarrhea. She has an elevated HR and tremor. ON physical exam you notice a goiter in the throat region. Thyroid biopsy reveals enlarged follicles with scalloping. What are the causes of exopthalmos and myxedema? What would lab findings reveal? What Tx would you provide?

A

GRAVES DISEASE - autoantibodies (IgG) stimulate TSH receptors on thyroid

  1. From Ab stiumulating TSH-R in fibroblasts –> INCR glycosoaminoglycans
  2. INCR Total/Free T3/T4, INCR glucose; DECR TSH and DECR cholesterol
  3. Beta blockers to dampen increased SANS activity and Thiomide to block peroxidase. Radioiodine ablation can also be done
37
Q

An extremely agitated 33 year old woman presents soon after childbirth. She had a very complicated delivery that required C-section. She seems delirious, and has diarrhea and fever. She starts vomiting, falls into a coma and expires from tachyarrhythmia. What was the underlying cause of her death, and what treatment could have saved her?

A

Thyroid Storm - from massive cateholamine surge (worst complication of Grave’s Disease)

Tx: 3 P’s –> Propranolol (Beta-blockers), Propylthiouracil, Prednisolone (corticosteroids)

38
Q

What are the characteristic features of a multionodular goiter and what is it’s cause? What is the risk of complication?

A

Enlarged thyroid gland with increased nodules

Caused by relative iodine deficiency

Can become toxic goiter where focal patches of hyperfunctioning follicular cells work independently of TSH (b/c of receptor mutation)

39
Q

What are 6 very characteristic features of congenital hypothyroidism (cretinism)?

A

6 P’s - Pot-bellied, Pale, Puffy-faced child, with Protruding umbilicis, Protuberant tongue, and Poor brain development

40
Q

What is the most common cause of cretinism in the US and what what is a common reason for dyshormonogenic goiter?

A

Dysgenesis of thyroid in US

Peroxidase deficient –> dyshormonogenic

41
Q

A patient presents with weight gain and decreased appetite. They complain of constipation, fatigue, and dyspnea on exertion. They also are cold intolerant and have decreased sweat production. On physical exam you notice dry, cool skin and coarse brittle hair. Patient also has an abnormally deep voice and edema with dull-like consistency in the face and periorbital regions. What is the cause for these symptoms and what are other symptoms that would be present? What would lab values reveal?

A

Hypothyroidism - can also have bradycardia w/ decr CO, oligomenorrhea

Labs: INCR TSH (primary hypothyroidism), and INCR cholesterol (from decrease LDL-R expression)
Decrease Free T3/T4

42
Q

A 34 year old man presents with fatigue and constipation. They have a moderately enlarged non-tender thyroid. Biopsy reveals lymphoid aggregate with germinal centers and Hurthle cells (surrounding cells with pink cytoplasm). Lab markers reveal increased anti-thyroid peroxidase and antithyroglobulin antibodies. What does this patient have and he at an increased risk for?

A

Hashimoto Thyroiditis - autoimmune destruction assoc. w/ HLA-DR5 (most common hypothyroid in iodine normal areas).

INCR risk for B-cell (non-Hodgkin) lymphoma, from germinal centers –> Marginal Zone –> lymphoma

43
Q

A 21 year old female presents after a recent flu infection with jaw pain and a very tender thyroid. Biopsy reveals granulomatous inflammation. What do they have and what is the course of disease as it relates to thyroid hormone?

A

Sub-acute (deQuervain’s) Thyroiditis - Self-limited hypothyroidism, with hyperthyroid possible early in course

44
Q

A 24 year old woman presents complaining of dysphagia and difficulty breathing. She also complains of fatigue, constipation, abnormal weight gain and a abnormal/missed menstrual cycles. She has a fixed, hard (rock-like) and painless neck mass. What does she have and what is the cause for it?

A

Riedel Thyroiditis - from thyroid replacement by fibrous tissue (hypothyroid)

IgG4-related systemic disease; fibrous deposits spread to airways, mimicking anaplastic CA of thyroid

45
Q

A patient presents with a distinct, solitary nodule in the thyroid. What key tests are necessary to investigate these signs and confirm the disease type?

A

131-iodine radioactive uptake studies

  • INCR uptake –> Graves, Nodular goiter
  • DECR uptake –> Adenoma, Carcinoma

FINE NEEDLE ASPIRATION BIOPSY (b/c very bloody tissue)

46
Q

A patient has a FNA biopsy done for a thyroid mass which reveals follicle proliferation surrounded by a dense pink fibrous capsule. There is no follicle proliferation past the fibrous capsule, what may this patient have?

A

Follicular Adenoma - benign tumor of follicular glands

47
Q

What are the four types of thyroid carcinoma?

A
  1. Papillary
  2. Medullary
  3. Follicular
  4. Anaplastic
48
Q

A patient presents with a thyroid mass. Biopsy reveals finger-like cells with “Orphan-Annie Eye” nuclei, nuclear grooves and psammoma bodies. There is spread of disease to cervical lymph nodes. What does this patient have and what is the prognosis? What made them at risk for this disease?

A

Papillary Carcinoma of Thyroid - Excellent prognosis (80% of CA in thyroid)

RIsks: RET and BRAF mutations, and irradiation as a child

49
Q

A patient presents with thyroid mass. Biopsy reveals a fibrous capsule with follicular proliferation. The follicles invade past the fibrous capsule. What does this patient have and could you have reached a diagnosis with FNA biopsy? What is the main risk with this CA?

A

Follicular Carcinoma of Thyroid - No!! Margins of capsule need to be seen or gross specimen to distinguish between follic. adenoma

High propensity for hematogenous spread

50
Q

What 4 carcinomas spread by hematological means first?

A
  1. Renal Cell CA - via Renal vein
  2. Hepatocellular CA - via Hepatic vein
  3. Follicular CA - via thyroid
  4. Chorio CA - VERY FAST SPREAD BY BLOOD
51
Q

A patient presents with hypocalcemia and thyroid mass; they have increased levels of calcitonin. FNA biopsy reveals malignant neoplastic cells w/in amyloid stroma (localized amyloidosis). Patient is also positive for RET mutation. What does this patient have and what may have been the familial cause of this?

A

Medullary CA of thyroid - malignant prolif of C-cells (parafollicular)

Familial Cause - Multiple Endocrine Neoplasia (MEN 2A and 2B)

52
Q

A 74 year old man presents complaining of dysphagia and difficulty breathing. He also complains of fatigue and weight loss. He has a fixed, hard (rock-like) and painless neck mass. What does he have and what would FNA biopsy reveal?

A

Anaplastic Carcinoma of Thyroid - undifferentiated malignant tumor w/ poor prognosis

Biopsy - Highly malignant cells (no similarity to thyroid cells) w/ invasion of local structures.

53
Q

What are the key features of hyperparathyroidism if it is symptomatic and lab findings?

A

Stones (hypercalcuria –> renal stone), bones (osteitis fibrosis cystica) , groans (weakness and constipation), and psychiatric overtones (CNS disturbance, depression, seizures)

All caused by INCR PTH and subsequent INCR Ca, decrease Phosphate

Urinary cAMP also increased, and serum Alk Phos increased (osteoblastic activity)

54
Q

What is the most common cause of secondary hyperparathyroidism and how does it arise?

A

Chornic renal failure –> renal insufficiency –> DECR phosphate excretion –> INCR serum phosphate binds free Ca –> DECR serum free Ca –> Stimulates all PT glands –> INCR PTH –> BONE RESORPTION

Alk PHos will also be increased

55
Q

A 34 year old female presents with numbness and tingling in the perioral region. You notice muscle spasms while taking her blood pressure (Trousseau sign) and when tapping the Cheek (Chvostek sign). She had a thyroidectomy a month ago. What will be the key lab findings, and what are other possible ways this can arise?

A

Hypoparathyroidism –> DECR PTH and DECR serum Ca

From surgery, autoimmune damage, or DiGeorge Syndrome (failure of development of craniopharyngeal pouches 3/4)

56
Q

What leads to development of pseudohypoparathyroidism? What are key features in patient with a genetic basis of this disease?

A

End-Organ resistance to PTH usually caused by defect in Gs protein subunit (this is responsible for activating adenylate cyclase, so you get decreased cAMP in end organ)

Autosomal Dominant – Short stature, short 4th and 5th digits

57
Q

Where is insulin produced and what is it’s main direct action?

A

beta cells in the center of islets of langerhans

upregulates Glut-4 receptor on skeletal muscle and adipose tissue –> increased lactogen, lipogenesis and protein synthesis

58
Q

What are the main results of insulin deficiency?

A

Decreased glucose uptake, increased protein catabolism, increased lipolysis

59
Q

A 12 year old boy presents with deep rapid breathing, abdominal pain and nausea/vomiting. You sense a fruity breath odor. What would lab findings reveal? How would you treat?

A

Diabetic ketoacidosis - T1 DM

  • Hyperglycemia (>300 mg/dL)
  • Anion gap metabolic acidosis –> INCR H+, DECR bicarb
  • Hyperkalemia (depleted intracell K+)
  • INCR blood ketones

Tx: IV fluids, IV insulin, and K+. Glucose to prevent hypoglycemia if necessary

60
Q

A 20 year old male with a BMI of 21 presents with weight loss, low muscle mass, polyphagia, polyuria, polydipsia, and glucoseuria. What reaction leads to his disorder? What may this patient have had years before presenting with symptoms?

A

TI DM - Type IV hypersensitivity reaction - autoimmune destruction of beta cells by T-lymphocytes
-Inflammation of islets, associated with HLADR3/DR4

-Autoantibodies against insulin

61
Q

A 56 year old obese woman presents with polyuria, polydipsia. A random glucose test gives a serum glucose level of 256 mg/dL. What key features would be present upon histological examination of her pancreas? How does obesity contribute to her disease?

A

Type 2 Diabetes
-Amyloid buildup in islets

-decreased insulin receptors on skeletal muscle and adipose tissue

62
Q

What are the best treatments for T2 DM?

A

Weight loss, metformin, insulin injections for end stage disease

63
Q

What are the two broad categories of manifestation of diabetes mellitus?

A

Nonezymatic glycosylation and Osmotic damage

64
Q

What will result from NEG of small vessels?

A

Small - diffuse thickening of basement membrane

Kidneys - Hyaline arteriosclerosis –> preferentially on efferent arteriole –> increased glmoerular pressure –> hyperfiltration injury –> sclerosing of mesangium –> Kimmelsteil wilson nodule –> NEPHROTIC SYNDROME

Eyes –> retinopathy, hemorrhage, blindness

65
Q

What will result from NEG of large vessels?

A

Large - Atherosclerosis –> Coronary Artery Disease, peripheral vascular disease, cerebrovascular disease

66
Q

What will occur with NEG of afferent arteriole of the kidney?

A

Diffuse sclerosis –> chronic failure

67
Q

What is the main mechanism for osmotic damage in diabetes mellitus and what are the three main areas where osmotic damage exerts its effects?

A

INCR glucose –> aldose reductase converts glucose to SORBITAL –> sorbital leads to osmotic damage

  1. Schwann Cells –> peripheral neuropathy
  2. Pericytes of retina –> Aneurysm –> hemorrhage –> blindness
  3. Lens –> cateracts
68
Q

A patient presents with episodic hypoglycemia with mental status changes. They complain of lethargy and syncope. Symptoms are relieved by giving glucose. What may this patient have and what will confirm this?

A

Insulinoma

Confirmed by DECR glucose, INCR insulin AND INCR C-Peptide

69
Q

A patient presents with abdominal pain and diarrhea. Endoscopy reveals multiple peptic ulcers extending into duodenum and jejunum. What may be the cause for this and what is this associated with?

A

Zollinger-Ellison syndrome from a Gastrinoma

may be associated with MEN 1

70
Q

What specific tumor type would result in achlorydia, cholelithiasis, and steatorrhea?

Wat about watery diarrhea, hypokalemia and achlorydia?

A

Somatostatinoma –> inhibition of cholecystokinin and gastrin

VIPoma

71
Q

Which organ is most commonly affected by carcinoid (neuroendocrine) tumors and what are the rules governing its spread? When will the effects of carcinoid syndrome be apparent when it is in this organ?

A

Most common malignancy of small intestine

Rule of 1/3s: 1/3 metastasize, 1/3 present w/ 2nd malignancy, 1/3 are multiple

When spread from GI to liver, the secreted 5HT bypasses first pass metabolism by liver, exerting its effects.

72
Q

A 34 year old female presents with muscle weakness and unusual weight gain, especially in the abdominal region. On physical exam you notice thin extremities with moon facies, and abdominal striae. She is also hypertensive. Patient has a history of asthma, for which she was prescribed corticosteroids, but she hasn’t followed up with her physician in some time. What would you most likely find if you examined her adrenal glands?

A

Cushing Syndrome - from exogenous corticosteroid use

BILATERAL ATROPHY of glands because of DECR ACTH

73
Q

A 48 year old man presents with muscle weakness and HTN. You notice truncal obesity with abdominal striae and a buffalo hump. He also complains that he has recently kept getting sick. Ultrasound reveals Adrenal gland hypertrophy, bilaterally. What should you check for next, and how can you confirm his diagnosis?

A
  1. 24 hr urine cortisol levels to confirm Cushing syndrome
  2. High Dose dexamethesone Test - with monitoring of cortisol levels
    - If ACTH production is suppressed –> Pituitary Adenoma
    - If ACTH cannot be suppressed –> Small Cell Lung CA most likely (or some other paraneoplastic CA)
74
Q

A patient presents with cushing syndrome and one adrenal gland is atrophic while the other is slightly enlarged. What are possible causes for this and why?

A

Primary Adrenal adenoma, adrenal hyperplasia, or adrenal carcinoma

-Pathology in one adrenal gland –> INCR cortisol to anterior pituitary –> DECR ACTH –> unaffected adrenal gland becomes atrophic from low ACTH

75
Q

Aside from the characteristic weight gain, HTN, muscle weakness, and abdominal stria, what are other characteristic symptoms of Cushing Syndrome, and how did they arise?

A
  1. Osteoporosis
  2. Amenorrhea
  3. Immune suppression –> From cortisol inhibiting Phospholipase A2, IL2 (B-cell growth factor), and HIstamine
76
Q

A patient presents with hypertension, hypernatremia, hypokalemia, and metabolic alkalosis. Further imaging reveals an adrenal mass. What does this patient have and what key lab findings would be present? Possible Treatments?

A

Primary Hyperaldosteronism - via adrenal hyperplasia or adrenal adenoma (conn syndrome)

INCR aldosterone and DECR renin

Tx: Surgery to remove and Spironolactone (a K sparing diuretic that acts as an aldosterone antagonist)

77
Q

A patient presents with HTN, hypokalemia, hypernatremia, and metabolic alkalosis. Further lab findings reveal an elevated serum aldosterone and renin. What are the possible causes for this?

A

Secondary Hyperaldosteronism

  • Young female –> Fibromuscular dysplasia of renal artery
  • Old Man –> Atherosclerosis of renal artery
78
Q

A 54 year old man with a 30 pack year history of smoking presents with weakness, vomiting and diarrhea. You notice that he is hypotensive and has hyperpigmentation of his skin and gums. Lab values reveal hyponatremia and hyperkalemia. You also suspect he is hypovolemic. What is the underlying cause for his symptoms?

A

Metastatic Carcinoma from the lungs to adrenal gland –> chronic adrenal insufficiency

Result is Adrenal Atrophy and Absence of hormone production, involves All 3 cortical divisions

79
Q

What are the possible causes of adrenal insufficiency in a chronic state (Addison disease)?

A
  1. Autoimmune destruction (common in west)
  2. TB (common in 3rd world)
  3. Metastatic Carcinoma (lung cancer loves to go to adrenal, much less common cause of Addison’s)
80
Q

A 6 year old boy presents in an extremely hypertensive state. He is vomiting and had a neisseria meningitits infection which progressed to DIC. The child eventually expires and autopsy is performed. What would you find on gross examination?

A

Waterhouse-Friderichsen syndrome

Sack of blood adrenal gland appearance.

81
Q

A 2 year old girl presents with abdominal distension and a firm, irregular mass that corsses the midline. HIstology reveals rosettes and small, round, blue/purple nuclei, and is Bombesin +. What compound would be elevated in the urine, and what gene may be overexpressed?

A

Neuroblastoma

Homovanillic Acid (HVA) increased in urine (breakdown product of dopamine).

Overexpression of N-myc oncogene

82
Q

A 43 year old man presents with episodic HTN and headaches. He also complains of occasional heart palpitations and excessive sweating. Lab results reveal increased serum metanephrines and increased 24 hour urine metanephrines and VMA. What would be the next step in treatment and what would treatment reveal?

A

Pheochromocytoma - tumor of chromaffin cells in adrenal medulla –> increased catecholamines

Tx –> Give irreversible alpha-antagonists (phenoxybenzamine) and beta-blockers, followed by tumor resection

Gross exam: Brown tumor in adrenal gland w/ thin yellow streak (adrenal cortex)

83
Q

What are 5 key useful symptoms apparent in pheochromocytoma?

A 
5 P's - Episodic hyperadrenergic symptoms
Pressure (increased BP)
Pain (headache)
Perspiration
Palpitations (tachycardia)
Pallor
84
Q

What are the rule of 10’s associated with pheochromocytoma?

A 
10% bilateral
10% familial
10% malignant
10% extra-adrenal
10% calcify
10% kids
85
Q

What are the major associated disorders that can lead to production of pheochromocytoma?

A
  1. MEN 2A/2B
  2. Von Hippel Landau Disease
  3. Neurofibramatosis Type 1
86
Q

A patient presents with pheochromocytoma and is found to have MEN 2A. What do you want to check for immediately?

A

check for RET gene to determine if phophylactic thyroid removal is necessary (to avoid medullary carcinoma)

USMLE Step 1 Prep (11 decks)

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