Endocrine

Question 0

Thyroid Nodules

Answer 0

• Imaging: US, Fine needle aspirate with cytology, I-scintiscan (will determine if hot or cold nodule). FNA is test of choice.
• Hot Nodule: Increased I uptake= functioning/hyperfunctioning nodule.
• Cold Nodule: Decreased I uptake= nonfunctioning nodule. More worrisome for being malignant.
• Surgical removal of the nodule if hx of radiation exposure.

Question 1

Hyperthyroidism

Answer 1

-Most common cause is Grave’s Disease. Other causes are toxic adenoma and toxic multinodular goiter.
-Sx: nervous, irritable, palpitations, heat intolerance/increased sweating, tremor, wt loss or gain, diarrhea, dyspnea, sleep disturbance, menstrual disturbance, impaired fertility, photophobia/eye irritation/exopthalmous, fatigue/muscle weakness, pretibial myxedema
-Graves: autoimmune-Trabs stimulate TSH receptor which increase thyroid hormone production. Sx= exopthalmos, pretibial myxedema, and non pitting edema. TSH is low, T4 elevated, and Trabs present. Can be diagnosed with radioactive iodine uptake but not always necessary.
Tx= antithyroid drugs(PTU, methimazole), radioactive iodine, thyroidectomy.

Question 2

Thyroid-Neoplastic disease

Answer 2

• Thyroid carcinoma: History= neck radiation, FH, young age, m>f. Signs= single nodule, cold nodule, increased calcitonin levels, lymphadenopathy, hard/immobile. Sx: voice change, dysphagia, discomfort, rapid enlargement.
• 5 types: papillary adenocarcinoma, follicular, medullary, hurthle cell, anaplastic/undifferentiated.
• Sx: mass, lymphadenopathy
• Workup: FNA, US, TSH level, Ca level

Question 3

Hyperparathyroidism

Answer 3

• Increased secretion of PTH.
• Ca will be elevated, P will be low
• Primary= secretion by parathyroid. Most common cause is adenoma.
• Secondary= results from Ca wasting caused by renal failure or decreased GI Ca absorption.
• Tertiary= autonomous PTH secretion that is not responsive to the normal negative feedback
• Sx: kidney stones, bone pain, muscle pain/weakness, pancreatitis, gout, constipation, depression, wt loss, HTN, polydipsia/polyuria
• May see subperiosteal bone resorption - look at DEXA scan
• Tx: remove parathyroid gland-can implant into arm

Question 4

Hypoparathyroidism

Answer 4

-Most common after thyroidectomy.
-Sx: tetany, muscle cramps, convulsions, tingling around the mouth/hands/feet, lethargy, personality changes, Chvostek sign (facial m. contraction on tapping of facial nerve), Trousseau phenomenon (carpal spasm), cataracts, thin/brittle nails, dry skin, alopecia, hyperactive DTRs.
Labs: Ca low, P high, PTH low.
Tx: Calcium, Vit D analogs(Calcitriol).

Question 5

Adrenal-neoplastic disease

Answer 5

• Incidentaloma- found on CT. Most common cause is nonfunctioning adenoma. Resection indicated if solid and >6cm in diameter, if hormonally active, or enlarging cystic lesion.
• Adrenal adenoma or carcinoma can cause ACTH independent cushings syndrome. Need to use thin slice CT.
• Adrenal carcinoma= Necrosis, hemorrhage, and calcification.

Question 6

Pheochromocytoma

Answer 6

• Tumor of the adrenal medulla
• Produces catecholamines (NE>epi)
• RFs= MEN-II, FH, von recklinghausen, von hippel lindau
• Sx: palpitations, HA, diaphoresis, HTN, pallor->flushing, anxiety, wt loss, tachycardia, hyperglycemia
• Dx: urine screen for VMA, serum epi/NE levels
• Imaging: CT, MRI, IMIBG(NE analog-will collect in the tumor), PET scan, Octreoscan
• Pre-op tx: alpha blocker FIRST (phenoxybenzamine, prazosin) to reduce catecholamine induced vasoconstriction (increases the intravascular volume). THEN do beta blocker!
• Will need tumor resection. (TOC)

Question 7

Most common cause of thyroid enlargement?

Answer 7

-Multinodlular goiter-surgery for cosmetic reasons, compressive sx.

Question 8

Papillary Adenocarcinoma

Answer 8

• most common thyroid cancer (80%)
• radiation exposure puts one at risk
• good prognosis
• Thyroidectomy if greater than 1.5cm, b/l, with cervical node metastasis. Remove involved lymph nodes.
• Post op= Synthroid

Question 9

Follicular Adenocarcinoma

Answer 9

• Nodule is rubbery, encapsulated.
• good prognosis
• Tx= total thyroidectomy
• cannot be diagnosed by FNA-need tissue histology.

Question 10

Medullary Carcinoma

Answer 10

• Associated with MEN-II (autosomal dominant)-if genetic it is always in both lobes.
• Secretes Calcitonin (tumor marker)
• Dx= FNA
• Poor I uptake (unlike papillary and follicular)
• poor prognosis if LN spread.
• Tx: total thyroidectomy and median LN dissection.

Question 11

Anaplastic Carcinoma

Answer 11

• Histo findings= giant cells, spindle cells
• poor I uptake
• Dx= FNA
• Tx: Total thyroidectomy + chemo. Surgical resection is palliative airway relief.
• Very poor prognosis.
• Mostly older pts.
• Rapidly expanding