Endocrine Disorders

Question 1

mobile 1cm firm thyroid nodule. Risk factors for thyroid CA? Tx.

Answer 1

1. Radiation hx (most commonly papillary CA)
2. FHx

Tx for pts w/radiation exposure = thyroidectomy

Question 2

Inheritence pattern of medullary thyroid CA. Workup.

Answer 2

Autosomal dominant pattern d/t point mutation in RET gene. Measuring serum calcitonin levels (elevated in medullary CA). Consider MEN syndromes (20% of medullary thyroid CA) and evaluate for pheochromocytoma, adrenal medullary hyperplasia, and hyperparathyroidism. MEN type II is the most common form that includes medullary thyroid CA. NO USE for post-op radioactive iodine b/c the tumor arises from C-cells. Monitor recurrence w/serum calcitonin and CEA levels

Question 3

Solitary nodule vs. multinodular gland risk for CA. Cold vs. Hot noduel risk for CA

Answer 3

10% vs. 5%. Cold nodule > hot nodule risk for CA

Question 4

If nodule is solitary and not hard or fixed what is the next thing to do?

Answer 4

Fine needle aspiration with cytology analysis of aspirate.

Question 5

Workup for cyst and for recurrent cyst.

Answer 5

Cyst requires complete aspiration and follow up. A recurrent OR large cyst requires removal to eliminate risk of malgnancy
TFT’s are NOT necessary for workup of thyroid noduels

Question 6

Workup for thyroid nodule evaluation

Answer 6

1. Radioactive iodine is NOT appropriate in the initial evaluation.

Question 7

Colloid nodule

Answer 7

Benign condition w/o need for surgery (no malignant risk) - medical mgmt w/thyroid suppresion is sufficient

Question 8

Thyroid mass w/psammoma bodies. Most common thyroid tumor type. a/w thyroid radiation exposure.

Answer 8

Papillary CA of thyroid. Total thyroidectomy OR limited thyroid lobectomy and isthmusectomy in some cases. Prophylactic neck LN dissection may be performed to prevent mets. Prognosis depends on age, pathologic grade, extent of disease, size of tumor. Postoperatively req’s the use of thyroid hormone +/- radioactive iodine for ablation

Question 9

Thyroid mass w/amyloid deposits

Answer 9

Amyloid and calcitonin staining suggest medullary thyroid CA. total thyroidectomy indicated.

Question 10

Thyroid mass w/Undifferentiated cells. CA is advanced stage at onset.

Answer 10

Must perform CTX and radiation or salvage operative therapy. Surgical options are limited…must remove tumor from the trachea to prevent respiratory compromise. Often presents with distant mets and prognosis is POOR!

Question 11

Thyroid mass w/Hurthle cells

Answer 11

Adenoma or low-grade CA requiring lobectomy

Question 12

Thyroid mass w/follicular cells. More prevelant in iodine deficient areas. Propensity for vascular spread and not lymphatic spread.

Answer 12

Lobectomy and isthmusectomy are indicated for well-circumscribed lesions (microinvasive). Total thyroidectomy is req’d for microinvasive lesions >4cm. Post-op radioactive iodine ablation reqd. Worse prognosis b/c of vascular invasion.

Question 13

Thyroid mass w/ymphocytic infiltrate

Answer 13

Lymphoma or chronic lymphocytic thyroiditis (differentiated by flow cytometry)

Question 14

Risks a/w thyroid surgery

Answer 14

1. Injury to recurrent laryngeal nerve
2. Injury to external branch of superior laryngeal nerves (responsible for high pitched singing voice)
3. Injury to the parathyroid gland resulting in hypocalcemia AND hyper phosphatemia

Question 15

Unilateral vs. bilateral injury to recurrent laryngeal nerves

Answer 15

1. Unilateral = hoarse voice

2. Bilateral = vocal cord paralysis requiring tracheostomy

Question 16

Hypercalcemia, bone reabsorption, generalzied fatigue, osteitis fibrosa cystica. Workup. Tx.

Answer 16

Measure PTH, alk phos, and phosphate levels. Primary PTH will show elevation in BOTH Ca and PTH. Most common cause of primary PTH is a parathyroid adenoma. Parathyroid adenomas are resected and all 3 other glands must be ID’d w/biopsy to r/o malignancy. Sestamibi scan may be done pre-op to localize the enlarged glands and thus allowing for conservative incision size.

Question 17

If only 3/4 of PTH glands are ID’d what is the most likely location of the missing gland?

Answer 17

The thymus (may require thymectomy), the tracheoesophageal groove and in the carotid sheath. If the last gland cannot be ID’d then localization studies must be done including sestamibi scans, US, CT, MRI, angiography, or venous sampling

Question 18

Risks of PTH surgery

Answer 18

1. Injury to recurrent laryngeal nerve
2. Injury to external branch of hte superior laryngeal nerve
3. HypoPTH (hypocalcemia and hyperphosphatemia). May result in tetany, Chvostek’s sign.

Question 19

Nausea, fatigue, wt loss, drowsiness, abd pain, altered mental status, BP d/o, kidney stones, hypercalcemia

Answer 19

1. Metastatic CA from breast = #1 malignant cause of hypercalcemia
2. PTH hyperplasia
3. multiple myeloma
4. HyperPTH
5. Sarcoidosis
6. Milkl alkali syndrome
7. Vit A tox
8. Thiazie diuretics
9. RCC
10. SCC of lung (PTHrP release)
11. Familial hypocalciuric hypercalcemia

Question 20

Consequences of hyperCa2+

Answer 20

Osmotic diuresis resulting in dehydration and worsening hyperCa2+. Requires rehydration followed by furosemide to cause Ca2+ loss, initiation of bisphosphonates, and treatment of the underlying disorder

Question 21

Tx for primary hyperPTH

Answer 21

1. Neck exploration and removal of abnormal PTH glands

Question 22

Renal failure, hyperphosphatemia, hypoCa2+, elevated PTH

Answer 22

1. secondary hyperPTH d/t increased Ca2+ absortion from the gut and vit D metabolism

Question 23

Medical vs. surgical mgmt of 2ndary hyperCa2+

Answer 23

1. Chronic renal failure requires medical mgmt
2. Bone pain, fractures, intractable pruritus, ectopic Ca2+ of soft tissue requires surgical mgmt (Removal of all but 50mg of PTH tissue which may be transplanted to more accessible sites such as the forearm in case further surgery is needed)

Question 24

Ca2+ changes in pt w/renal transplant. Tx.

Answer 24

Return to normal PTH function usually occurs but high serum Ca2+ may occur post-op (aka tertiary hyperPTH). In this case the PTH dont respond to return of normal renal fxn and continue to overproduce PTH. 3.5 gland resection is indicated.

Question 25

Pt undergoing neck exploration for HyperPTH becomes uncontrollably HTN

Answer 25

May be d/t catecholamine release from undiagnosed Pheochromocytoma. Must STOP SURGERY and admit to ICU. Give both alpha AND beta blockers to control HTN (NEVER USE BETA BLOCK ALONE d/t uncontrolled alpha that results)

Question 26

markers for pheochromocytoma

Answer 26

1. Elevated urinary catecholamines (metanephrine, vanillylmandelic acid) 2. MRI demonstrating tumor of adrenals 3. Octreotide scan used for hard-to-locate tumors 4. nuclear iodine metaiodobenzylguianidine scan (MIBG accumulates in chromaffin tissue with HIGH specificity for pheochromocytoma)

Question 27

Approach to tx of pheochromocytoma

Answer 27

1. Phenoxybenazmine (alpha block) must be taken for 10-14d pre-op to prevent HTN crisis 2. Surgical resection of adrenals

Question 28

Tender swollen neck mass with elevated ESR. Granulomatous histology with degenerating thyroid follicles. Tx.

Answer 28

Painful thyroiditis from de Quervain's thyroiditis. Sudden release of thyroid hormone from acutely injured thyroid follicles. Tx = analgesics and aspirin. Steroids may be used in resistant cases. Surgery NOT indicated unless there is a bacterial infxn by strep, staph, pseudomonas, TB, aspergillosis, actinomycoses, and syphilis (acute suppurative thyroiditis)

Question 29

PainLESS thyroid mass with hypertrophy. Replacement of damaged thyroid tissue with lymphocytes and plasma cells. HYPOthyroid state with low T3 and T4. NORMAL TSH. Tx.

Answer 29

Hashimoto's thyroiditis (chronic lymphocytic thyroiditis). Tx = thyroid resection w/biopsy of suspicious lesions. If compression of trachea occurs then palliative resection is indicated.

Question 30

What is Hashimosto's thyroiditis?

Answer 30

Replacing immune damaged thyroid tissue with lymphocytes and plasma cells resulting in an enlarged painless mass a/w low T3/T4 and normal TSH. Hashimoto's is a/w higher risk of Papillary CA and thyroid lymphoma

Question 31

Pt w/hx of HyperPTH and intractable duodenal ulcers s/p parathyroidectomy for HyperCa2+

Answer 31

Zollinger Ellison syndrome (2 forms sporadic vs. familial a/w MEN syndromes) MEN1 (pituitary adenoma causing vision symptoms or lactation, PTH hyperplasia, pancreatic tumor causing gastrinoma, insulinoma, VIPoma)

Question 32

Workup for Zollinger elison tumor

Answer 32

1. Localize gastrin secreting tumor by CT and MRI (usually at the head of the pancreas or within the duodenal wall) 2. Endoscopic US 3. Angiogram 4. Venous sampling for gastrin

Question 33

Tx for gastrinomas

Answer 33

1. Malignant tumors spread to the LN's AND especially the liver. Therefore surgery may only be useful if performed early before metastasis occurs. 2. As much tumor as possible should be removed while preserving the pancreatic mass. However if the mass involves the large pancreatic duct a Whipple procedure (distal pancreatectomy) should be performed. 3. However, if the tumors are not resectable should undergo gastric resection or selective vagotomy. 4. CTX include Streptozocin for tumor control.

Question 34

Fasting hypoglycemia <60mg/dL, symptomatic hypoglycemia, relief by glucose administration, elevated C-peptide

Answer 34

Insulinoma (usually a/w MEN syndromes)

Question 35

Tx of insulinoma

Answer 35

1. Unresectable insulinomas should be tx w/diazoxide to inhibit insulin release

Question 36

Thyroid mass with amyloid like material and C-cell proliferation on FNA.

Answer 36

Medullary CA of the thyroid. Often a/w MEN-2a or MEN-2b syndrome (AD inheritence) 1. MEN-2a = medullary thyroid CA, parathyroid hyperplasia, pheochromocytoma 2. MEN-2b = MEN-2a + marfanoid body habitus AND ganglioneuromas

Question 37

Frontal pounding HA, episodic diaphoresis, palpitations, anxiety, episodic/sustained HTN

Answer 37

Pheochromocytoma (BL>sporadic)

Question 38

Tx for medullary thyroid CA

Answer 38

total thyroidecomy + LN's in central neck compartment

Question 39

Tx of incidental adrenal mass

Answer 39

Depends on size of mass and symptoms. 1. Adrenal cortical CA = surgical resection of adrenal gland 2. Small adrenal mass that is functional must be removed 3. Small adrenal mass that is NONfuncitonal must simply be followed w/close observation.