Endocrine Dysfunction

Question 1

Thyroid Hormone Pathway

Answer 1

Brainstem/Paraventricular nucleus releases TRH; which acts on anterior pituitary; which releases TSH; which acts on the thyroid gland; which releases T4 and T3; which impact all cells of the body.

Question 2

Thyroid hormone is transported in the blood via

Answer 2

proteins secreted by the liver

Question 3

T3 is a nuclear transcription factor

Answer 3

drives transcription and translation in other cells of the body.

Question 4

Hyperthyroidism (Thyrotoxicosis). Too much thyroid hormone. Symptoms:

Answer 4

Abdominal pain, vomiting, weight loss despite increase in appetite

Question 5

Hyperthyroidism associated with:

Answer 5

Pernicious anemia affecting stomach, celiac, IBD

Question 6

Upper GI tract symptoms of hyperthyroidism:

Answer 6

• Dysphagia 2/2 goiter compression, neurohormonal regulation, skeletal myopathy affecting pharynx and upper esophagus.
  -Atrophic gastritis (autoimmune, graves, pernicious anemia), achlorhydria, hypergastrinemia, recurrence of H pylori.

Question 7

Hyperthyroidism and motility issues

Answer 7

• Esophageal contractility increases velocity of esophageal contractions.
• Gastric emptying can be increased or decreased.
• Accelerated transit can cause diarrhea, steatorrhea.

Question 8

Hyperthyroidism and lower GI tract symptoms

Answer 8

Lactose intolerance.

Question 9

Hypothyroidism (Hashimoto’s thyroiditis). Too little thyroid hormone symptoms:

Answer 9

anorexia, nausea, vomiting, abdominal pain, constipation.
weight gain due to myxedema,
anemia: menorrhagia, pernicious anemia/achlorhydria
ascites due to myxedema (high protein content).
- GI bleeding
- GI disease (celiac) can affect absorption of oral thyroid hormone replacement

Question 10

Hypothyroidism is associated with

Answer 10

IBD, Pernicious anemia/B12 malabsorption, DM, Celiac, T21,

Question 11

Hypothyroidism motility problems

Answer 11

-Esophageal motor and LES/goiter: dysphagia and dyspepsia.
- GER (Esophageal/LES)
- Delayed gastric emptying: phytobezoars.
- Ileus: SBBO: pain, bloating, flatulence.
- Megacolon, constipation, colonic pseudo-obstruction.

Question 12

Hyperparathyroidism (Hypercalcemia due to elevated PTH). DDX:

Answer 12

• Sporadic adenoma.
• MEN types I-4.
• Other: post renal transplant, chronic hyperphosphatemia, bone malignancy.

Question 13

Hyperparathyroidism symptoms

Answer 13

• Gastroparesis: N/V, abdominal pain.
• PUD (gastric hypersecretion). Ca drives gastric acid.
• Decreased colonic transit (constipation)
• Pancreatitis (acute and chronic): abdominal pain and steatorrhea.

Question 14

Hypoparathyroidism (Hypocalcemia). Congenital causes

Answer 14

-Congenital (suspect in infants with tremor, jitteriness, emesis, feeding issues). DiGeorge (microdeletion in chromosome 22q11.2).
- Other genes: PTH1R

Question 15

Hypoparathyroidism Acquired

Answer 15

AIRE (autoimmune polyendocrinopathy syndrome type I), IPEX, post -surgical, radiation destruction.

Question 16

Hypoparathyroidism Infiltrative

Answer 16

Wilson’s, Hemochromatosis, Neoplasm, Sarcoidosis

Question 17

Other causes of hypoparathyroidism include

Answer 17

Hypomagnesemia/hypermagnesemia

Question 18

Hypoparathyroidism (low calcium) impacts on GI tract

Answer 18

-low Ca causes decreased cholecystokinin (liver: steatorrhea, poor GB contractility; pancreas: decreased enzyme secretion).

Question 19

Hypoparathyroidism associations

Answer 19

Celiac
Steatorrhea
Vitamin D deficiency

Question 20

Cushing’s disease (Chronic glucocorticoid excess) symptoms

Answer 20

Cushingoid facies, buffalo hump, failure of longitudinal growth, hirsutism, muscle weakness, acne, striae, hypertension. DM

Question 21

Considerations if Cushing’s disease is central in origin

Answer 21

elevated serum ACTH and cortisol level can cause gastric ulceration (particularly if associated with NSAID use)

Question 22

Cushing’s syndrome and increased serum growth hormone levels associated with

Answer 22

colorectal polyps and cancer.

Question 23

Addison’s disease (adrenal insufficiency) symptoms.

Answer 23

Acute: low BP, shock, weakness, apathy, confusion, anorexia, nausea, vomiting, dehydration, abdominal pain, hyperthermia, hypoglycemia.
chronic: weakness, fatigue, anorexia, hypotension and hyperpigmentation.
Symptoms can be cyclical and mistaken for CVS

Question 24

Addison’s disease and enterocyte dysfunction

Answer 24

diarrhea, malabsorption, FTT

Question 25

Addison’s disease associated with

Answer 25

pernicious anemia (atrophic gastritis and achlorhydria), celiac disease.

Question 26

MEN genotypes

Answer 26

MEN type 1: MEN1
MEN type 2a: RET
MEN type 2b: RET

Question 27

MEN1

Answer 27

Gene: MEN1.
Autosomal dominant, rarely denovo.
constellation of tumors (often bilateral and multiple), parathyroid, pituitary, pancreas, duodenum.
presents as hyperparathyroidism and anterior pituitary tumors (can release prolactin, GH, ACTH).
carcinoids (neuroendocrine tumors of GI tract). Gastrinoma (ZE syndrome), Insulinoma, Somatostainoma

Question 28

MEN 1 Does NOT have

Answer 28

Medullary thyroid carcinoma or Pheochromocytoma.

Question 29

MEN 2A

Answer 29

Gene: RET, autosomal dominant.
Paraganglionomas.
BIlatreal medullary thyroid carcinoma and bilateral (70%) pheochromocytoma.
Primary hyperparathyroidism.

Question 30

MEN 2B

Answer 30

Gene: RET: Denovo. more aggressive.
Mucosal neuronal phenotype. Lots of ganglionomas of lips, tongue,
-100% medullary thyroid carcinoma, 50% pheochromocytoma

Question 31

MEN 2A and 2B do not have

Answer 31

Pancreatic neuroendocrine tumors