ENDOCRINE REVIEW
Topics: thyroid, parathyroid, adrenals, pancreas,
miscellaneous
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A 40 y/o man presents with weakness and easy
fatigability of 2 months duration. PE is
unremarkable. Lab studies show serum calcium
of 11.5, inorganic phosphorous 2.4, and high
serum PTH level of 58. A radionuclide bone scan
fails to show any areas of increased uptake.
Which of the following is the most likely cause of
these findings?
A) Chronic renal failure
 B) Parathyroid adenoma
 C) Parathyroid carcinoma
 D) Parathyroid hyperplasia
 E) Hypervitaminosis D
 F) Medullary thyroid carcinoma
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HYPERPARATHYROIDISM
The answer is B
 Primary hyperparathyroidism

Most common cause is a pituitary adenoma.
Increased PTH causes an elevation in calcium and a
decrease in phosphate levels
 STONES, BONES, GROANS, AND PSYCHIC
OVERTONES
 Osteitis fibrosa cystica- bone pain and brown tumors
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Secondary hyperparathyroidism
Chronic renal disease (beware of a DM patient in q stem)
causes retention of phosphorous which drives calcium levels
down and PTH secretion up parathyroid hyperplasia
 LOW calcium levels, HIGH phosphate due to retention
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A 50-year-old man has been diagnosed with a
follicular neoplasm of the thyroid. He undergoes
a total thyroidectomy. Within a day following
surgery, he is noted to have tingling sensations
and neuromuscular irritability. Which of the
following serum laboratory tests should be
ordered immediately to determine further
therapy for this man?
 A) TSH
 B) Parathormone
 C) Total thyroxine
 D) Ionized calcium
 E) Calcitonin
 F) Iodine
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HYPOPARATHYROIDISM
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The answer is D
The parathyroids can be inadvertently removed or
traumatized with thyroid surgery, resulting in postoperative hypocalcemia
Patients will have LOW serum calcium leading to
tetany (remember DiGeorge syndrome or thyroid
surgery)
Chvostek’s sign and Trousseau’s sign, carpopedal
spasm
Pseudohypoparathyroidism
 AD
condition where the kidney does not respond to PTH
leading to increased PTH
 Pts will have shortened stature and shortened 4th/5th digits
and MR

A 27 y/o woman experienced sudden severe abdominal
pain. On PE, she had marked abdominal tenderness
and guarding. Labs: serum glucose 76, calcium 12.2,
phosphorous 2.6, parathyroid hormone 62. During
surgery 4 enlarged parathyroid glands were removed.
After surgery her serum calcium returned to normal.
Three years later she develops upper GI hemorrhage.
An endoscopy and biopsy show multiple gastric
ulcerations. Abdominal MRI shows multiple mass
lesions in the pancreas. In surgery, multiple
gastrinomas are found. Two years later she develops
galactorrhea. Which of the following lesions is now
most likely to be present?
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A) Medullary carcinoma of the thyroid
B) Adrenal pheochromocytoma
C) Small cell anaplastic carcinoma of the lung
D) Endometrial carcinoma
E) Pituitary adenoma
MEN SYNDROME
The Answer is E
 The patient has MEN I syndrome
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MEN IIA
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Medullary carcinoma of thyroid, pheochromocytoma,
parathroid
MEN IIB
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3 P’s: pancreas (insulinoma, gastrinoma, VIPoma),
parathyroid, pituitary (adenoma)
Medullary carcinoma of thyroid, pheochromocytoma.
mucosal neuromas, intestinal ganglioneuromas,
marfanoid features, delayed puberty
All are autosomal dominant
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A 57-year-old man is found comatose. On
physical examination he has decreased skin
turgor. Laboratory studies show a blood glucose
of 780 mg/dl. Urinalysis reveals no ketosis or
proteinuria, though there is 4+ glucosuria. Which
of the following is the most likely diagnosis?
A) Islet cell tumor secreting glucagon
 B) Type I diabetes mellitus
 C) Cushing syndrome
 D) Ingestion of a large quantity of sugar
 E) Type II diabetes mellitus
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DIABETES COMPLICATIONS
The answer is E
 The complication of diabetes mellitus known as
nonketotic hyperosmolar coma is most typical for
type II diabetes mellitus
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Most affected persons have increased insulin
resistance, not an absolute lack of insulin secretion.
Thus, there is NO ketoacidosis accompanying the
hyperglycemia.
DKA is seen in DM I patients with an increased
anion gap metabolic acidosis
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Key is pts will have ELEVATED blood and urinary
ketones

A 45 y/o man feels a small lump on the side of his
neck. His doctor palpates a firm, painless, 1.5 cm
cervical lymph node. The thyroid gland is not
enlarged. Labs include serum glucose of 83,
creatinine 1.2, calcium 9.1, phosphorous of 3.3,
thyroxine 8.7, and TSH 2.3. A FNA of the
thyroid gland is performed and the cells are
examined microscopically. Which of the following
is the most likely diagnosis?
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A) Papillary carcinoma
B) Parathyroid carcinoma
C) Medullary carcinoma
D) Follicular carcinoma
E) Anaplastic carcinoma
THYROID CANCER
The answer is A
 Papillary carcinoma
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Most common
 Psammoma bodies
 LYMPHATIC INVASION
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Follicular
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Medullary
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HEMATOGENOUS SPREAD- mets to bone, lung,
liver
From C cells that make CALCITONIN and stain
positive with Congo red staining
Anaplastic
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BAD: Older patients; uncommon; poor prognosis
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A 40-year-old woman notes increasing enlargement
and discomfort in her neck over the past week. Her
doctor palpates a diffuse, symmetrical enlargement
with tenderness in the region of the thyroid gland.
Thyroid function tests show serum TSH of 0.8 mU/L
and thyroxine of 11.9 micrograms/dL. She is referred
to an endocrinologist, but the next available
appointment is in 8 weeks. When the endocrinologist
examines the patient, the thyroid is no longer
palpable and there is no pain. Repeat thyroid function
tests reveal a serum TSH of 3.8 mU/L and thyroxine
of 5.7 micrograms/dL. Which of the following thyroid
diseases is most likely to produce these findings?
A) Toxic multinodular goiter
B) DeQuervain (subacute) thyroiditis
C) Hashimoto thyroiditis
D) Graves disease
E) Riedel thyroiditis
F) Iodine deficiency
THYROIDITIS
The answer is B
 Subacute (de Quervain’s) thyroiditis

Self-limited disease
 Patients may initially be hyperthyroid, then
hypothyroid, then euthyroid due to transient damage
of thyroid follicles
 Tender thryoid and post-viral infection common
 Decreased uptake on thyroid scan
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Toxic multinodular goiter (Plummer syndrome)
Hyperfunctioning nodule within a goiter
 Will not produce signs of inflammation. Increased
levels of T3/T4 released and produced a HOT nodule
on thyroid scan
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A 2 y/o male child is brought to the doctor due to
FTT. PE shows the child is short and has coarse
facial features, a protruding tongue, and an
umbilical hernia. Profound MR is apparent. A
deficiency of which of the following hormones is
most likely to explain these findings?
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A) corstisol
B) norepinephrine
C) somatostatin
D) thyroxine
E) insulin
CRETINISM
The answer is D
 Cretinism
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Uncommon when there is routine testing and
treatment at birth
 Due to lack of maternal dietary iodine in pregnancy
 Myxedema is the term used for older children and
adults
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A 46 y/o woman has experienced a feeling of
fullness in her neck for the past year. Her energy
level is decreased. Her thyroid gland is diffusely
and symmetrically enlarged and non tender. She
has dry, course skin and alopecia. The figure
shows the microscopic appearance of the thyroid.
Which of the following antibodies is likely to be
found in this patients serum?
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A) Antimitochondrial
B) Antithyroid peroxidase
C) Anti- double stranded DNA
D) Anti- Jo 1
E) Anti-parietal cell
F) Anti- centromere
G) Anti- TSH R
HASHIMOTOS THYROIDITIS
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The answer is B
Hashimotos thyroiditis
+ antithyroid peroxidase (microsomal) and
antithyroglobulin antibodies
 Hurthle cells (pink)
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Other autoantibodies: MUST KNOW FOR STEP 1
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Antimitochondrial- primary biliary sclerosis
Anti- double stranded DNA- specific for SLE
Anti- Jo 1- polymyositis
Anti-parietal cell- pernicious anemia
Anti- centromere- scleroderma (CREST)
Graves disease
Cause of hyperthyroidism
 Autoantibodies bind to the TSH receptor and mimic action
of TSH leading to increased levels of T4 and ultimately
decreased levels of TSH
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The mother of an 11-month-old infant had noted
enlargement of the baby's abdomen within the past
month. This is confirmed by the osteopathic
physician, who notes that the baby is otherwise
normally developed. An abdominal CT scan reveals a
6 cm mass, with some scattered calcifications, above
the kidney on the right. Laboratory studies show a
greatly elevated urinary vanillylmandelic acid (VMA),
while the urinary homovanillic acid (HVA) is only
slightly increased. The mass is removed and
microscopically is composed of sheets of small blue
cells. Which of the following is the most likely
diagnosis?
A) Congenital adrenal hyperplasia
B) Adrenal cortical carcinoma
C) Neuroblastoma
D) Non-Hodgkin lymphoma
E) Pheochromocytoma
F) Aldosteronoma
NEUROBLASTOMA
The answer is C
 The baby has a neuroblastoma, one of the most
common childhood tumors
 These tumors produce catecholamine precursors
such as vanillylmandelic acid (VMA) and
homovanillic acid (HVA) in small amounts, so
hypertension is unusual.
 Adults will have the equivalent to this tumor =
pheochromocytoma

A 45-year-old man has a 4 month history of nonfocal, generalized headaches. On physical
examination he is found to have a blood pressure
of 170/110 mm Hg. Laboratory studies show a
serum sodium of 146 mmol/L, potassium 2.3
mmol/L, chloride 103 mmol/L, CO2 27 mmol/L,
glucose 82 mg/dL, and creatinine 1.2 mg/dL. His
plasma renin activity is 0.1 ng/mL/hr and his
serum aldosterone 65 ng/mL. Which of the
following is the most likely cause for his findings?
 A) 21-hydroxylase enzyme deficiency
 B) Adrenal cortical adenoma
 C) Pituitary adenoma
 D) Exogenous corticosteroid administration
 E) Renal cell carcinoma

HYPERALDOSTERONISM
The answer is B
 Primary hyperaldosteronism (Conn syndrome)

The history points to an aldosterone secreting
neoplasm, which is usually a small adrenal cortical
adenoma adenoma
 High alderosterone causes HYPOKALEMIA,
metabolic alkalosis and LOW plasma renin levels
 Remember: HIGH ALDOSTERONE AND LOW
RENIN
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Secondary hyperaldosteronism
Usually due to renal artery stenosis- kidney has
decreased blood flow and that activates renin
 HIGH RENIN levels
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Over the past 6 months, a 42 y/o man has
experienced increasing fatigue and weight gain in
a truncal distribution. He has proximal muscle
weakness. Fasting serum glucose is 155, 8am
serum cortisol level is elevated at 54 and serum
corticotropin is 63. Which of the following tests is
most likely to be helpful in the diagnosis?
A) MRI of the brain
 B) Abdominal CT of the adrenals
 C) Serum assay for glycosylated hemoglobin
 D) Biopsy of the gastrocnemius
 E) Assay for urinary catecholamines
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CUSHING’S SYNDROME
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Cushing’s disease
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Primary adrenal hyperplasia/ neoplasia
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Low ACTH
Ectopic ACTH production
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Due to a primary pituitary adenoma leading to increased
ACTH
Small cell lung cancer can lead to increased ACTH
Iatrogenic
MOST COMMON
 Leads to decreased ACTH
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Aside: Addison’s disease
Deficiency of cortisol and aldosterone from adrenal atrophy
 SKIN HYPERPIGMENTATION from Increased ACTH
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A 15-year-old boy has had worsening headaches
for 2 months. On examination he has diminished
peripheral vision, but no loss of visual acuity. A
head CT scan reveals a 4 cm mass expanding the
sella turcica and eroding the sphenoid bone. The
mass is cystic with scattered calcifications. Which
of the following is the most likely diagnosis?
 A) Prolactinoma
 B) Metastatic seminoma
 C) Empty sella syndrome
 D) Glioblastoma multiforme
 E) Craniopharyngioma
 F) Osteosarcoma

CRANIOPHARYNGEOMA
The answer is E
 Craniopharyngioma

Rare and sporadic neoplasm of older children and
young adults
 Produce a mass effect in the region of the sella and
can impinge upon the optic chiasm.
 The microscopic features suggest embryologic origin
from Rathke's pouch
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Empty Sella Syndrome
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Rare and seen in obese women
Herniation of arachnoid through diaphragma sella
and hyperprolactinemia
TOPICS THAT YOU MAY SEE ON STEP 1 BUT
WERE NOT COVERED IN THIS REVIEW
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Pheochromocytoma– rare but boards love this
Q– remember rule of 10’s and the patient will
always have the classic presentation
DI and SIADH
Carcinoid syndrome- again this will have a
classic presentation- remember rule of 3’s (1/3
metastasize, 1/3 have a 2nd malignancy, 1/3
multiple)
Acromegaly
KNOW THE PHARM IN FIRST AID