Endocrinology Step 1 Review

Michael Keller

Introduction

• Physiology Tips– Arrows!!!!

• Thyroiditis• Cushing’s• Diabetes• Questions

Cushing’s Syndrome

• Prolonged exposure to high levels of glucocorticoids

• MCC = Iatrogenic• Pituitary• Adrenal• Ectopic

• Nelson’s Syndrome: adrenalectomy causes enlargement of pre-existing pituitary adenoma due to ACTH from Cortisol. Mass effects, hyperpigmentation.

Cushing’s Suspected

Low Dose Overnight Dexamthasome

No Cushing’s Syndrome

High Dose (8mg) Overnight Dexamethasone

Cushing’s Disease (pituitary)

ACTH Levels

Ectopic ACTH Producing Tumor

Primary Adrenal Cushing’s Syndrome

Elevated Cortisol

Suppressed Cortisol

Suppressed Cortisol

Elevated Cortisol

Elevated ACTH Low ACTH

Thyroiditis

• Acute Thyroiditis – bacterial infection, fever, chills, rapid onset PAINFUL gland WITH cervical adenopathy. Initial hyperthyroid then hypothyroid

• De Quervain’s Thyroiditis – Follows Flu-like illness, Very tender, PAINFUL gland with NO cervical adenopathy. Granulomatous inflammation. Initial Hyperthyroid then hypothyroid

• Subacute Lymphocytic Thyroiditis – Commonly Postpartum. PAINLESS. Initial Lymphocytic Thyrotoxicosis then hypothyroid– Look for Nervousness, tremulousness, warmth after delivery

• Riedel’s thyroiditis – Hypothyroid, FIXED, HARD, PAINLESS goiter. May cause tracheal obstruction.

Diabetes Mellitus Type 1

Diabetes Type 2

High Yield Complications of Diabetes

• Hyperglycemia causes all of this!!!• Most common cause of death = MI• Diabetic Neuropathy– Glucose -------------> Sorbitol = osmotic damage– No sorbitol dehydrogenase in Schwann cells, lens,

kidney cells. • Diabetic Nephropathy – NEG of BM = Permeability, thickening– NEG of efferent arterials = GFR = Mesangial Damage,

Kimmelstiel-Wilson Nodules

Aldose Reductase

Normal Glomerulus Diabetic Nephropathy

VS.

Diabetes Insipidus• Either Central – Lack of ADH or • Nephrogenic – Lack of Renal Response to ADH

• Serum Osmolality, Urine SG - <1.006 Diagnosis – 2 steps• 1. Water Deprivation does not Urine osmolality• 2. Give ADH – Central responds. Nephrogenic Doesn’t!

Treatment:• Central – Desmopressin• Nephrogenic – HCTZ, Indomethacin or amiloride

Question 1

A 42 year old man previously diagnosed with kidney stones complains of gnawing, burning epigastric pain. On questioning, he also notes moderate to severe diarrhea. Measurement of the patient's basal gastric output reveals that it is markedly elevated. These symptoms are likely the result of which of the following neoplastic syndromes.

A: Familial polyposis coliB: MEN IC: MEN IIAD: MEN IIB

Question 2

A 50 year old man presents to his physician with diarrhea, flushing and wheezing. Physical examination is significant for a grade 2/6 diastolic murmur located at the right sternal border at the 4th intercostal space, Which of the following substances' is most likely elevated in the patient’s urine.

A) 5 – Hydroxindoleacetic acid (5-HIAA)B) Homovanillic acid (HVA)C) PhenylalanineD) SelegilineE) Vanilylmandelic acid

Question 3

A 46 year old woman presents to her physician complaining of weakness and fatigue. On physical examination, her physician notices a 10-Ib weight gain since her last visit 6 months ago. Her blood pressure is 160/100. Blood tests reveal serum Na of 155 mEq/L, K of 2.8 mEq/L, and decreased serum renin. Which of the following is the most likely diagnosis?

A) Cushing SyndromeB) Diabetes MellitusC) PheochromocytomaD) Primary AldosteronismE) Secondary Aldosteronism

Question 4 A 27 year old woman complains that she is constantly thirsty and has to

urinate every 2 hours. Her plasma osmolality is 295 mOsm/kg, and her urine osmolality is 100 mOsm/kg. Her urine is negative for glucose. As part of a diagnostic workup, the patient is deprived of fluids for 3 hours. Her urine osmolality remains 100 mOsm/kg. One hour after injection of arginine vasopressin (AVP), her urine osmolality becomes 400 mOsm/kg. Which of the following is the most likely diagnosis?

A) Diabetes MellitusB) Nephrogenic diabetes insipidusC) Neurogenic diabetes insipidusD) Primary PolydipsiaE) SIADH

Question 5

A 13 year old girl complaining of visual deficits is diagnosed with a brain tumor. The mass is detectable in CT by the presence of opaque calcifications. MRI reveals destruction of more than 75% of the anterior pituitary gland. Which of the following clinical manifestations would be most likely in this patient?

A) Amenorrhea and galactorrheaB) Bilateral exophthalmos and palpitationsC) Coarse facial features and enlarged hands and feetD) Polydipsia, polyuria, and low urine osmolalityE) Weight gain, sluggishness and depression

Question 6 A 33-year-old Caucasian female presents with complaints of polyuria and

polydypsia of recent onset. She prefers cold beverages to quench her thirst. Her vitals are P 85/minute, BP 110/70mm Hg and RR 15/minute; she is afebrile.Lab results are:Hb 14 g/dLWBC 6,000/cmmPlatelets 280,000/cmmBlood Glucose 110 mg/dLSerum Na 143 mEq/LSerum K 4.1 mEq/LBicarbonate 26 mEq/LBUN 17 mg/dLSerum Creatinine 1.0 mg/dLSerum uric acid 10 mg/dLSerum osmolality 302 mOsml/kgUrine osmolality 180 mOsml/kgBased on these, which of the following is most consistent with this patient's findings?A. Primary polydypsiaB. Primary aldosteronismC. Osmotic diuresisD. SIADHE. Diabetes insipidus

Question 7 A 57 year old man with hypertension and coronary artery disease

presents to the clinic for his annual check-up. His physical examination is notable for a solitary thyroid nodule. The patient denies any symptoms such as cough, difficulty swallowing hoarseness. The physician refers him to an ENT specialist for further evaluation. Results of a fine needle aspiration are shown in the image. Which of the following thyroid tumors does this patient have?

A) AnaplasticB) FollicularC) Hurthle CellD) MedullaryE) Papillary

Question 8

A 52-year-old man with recently diagnosed type 2 diabetes mellitus comes to the physician for a follow-up examination. Physical examination shows no abnormalities. Laboratory studies show an increased hemoglobin A1c despite patient compliance with diet and exercise recommendations. Treatment with a sulfonylurea is started. What is the mechanism of action of this drug?

A) Increased entry of glucose into the muscle cellsB) Increased production of glucose from the liverC) Increased secretion of insulin from the pancreasD) Increased speed of carbohydrate absorption from

the intestines

Question 9

A 24-year-old woman delivered vaginally 8 months ago. Her delivery was complicated by postpartum hemorrhage requiring transfusion of two units of erythrocytes. She complains of amenorrhea since her delivery. She denies taking medications of having headaches or visual abnormalities. Her pregnancy test is negative. She was not able to breast feed her baby. What is the most likely diagnosis?

A) Asherman SyndromeB) Pituitary tumorC) Sheehan syndromeD) PCOS

Question 10 A 62 year old man with a long history of cigarette smoking develops high

blood pressure, a moon face and central obesity. Serum ACTH is increased, MRI studies of the pituitary and hypothalamus fail to demonstrate any tumors. A Chest X-ray film reveals a small tumor in the right upper lobe, and a biopsy is performed. Histologically, the tumor is composed of sheets of anaplastic cells with high nuclear/cytoplasmic ratio. Which of the following is the most likely diagnosis?

A) AdenocarcinomaB) Carcinoid TumorC) HamartomaD) Small Cell CarcinomaE) Squamous Cell Carcinoma