ABSITE Review Thyroid Parathyroid Adrenal January 26, 2012

Rapid Fire

Blood supply to the thyroid? Superior thyroid artery 1st branch of external carotid Inferior thyroid artery From thyrocervical trunk Ima artery From innominate or aorta

The recurrent laryngeal nerve loops around what? Right subclavian (sometimes innominate) Aorta on left

If you find a non-recurrent nerve, which side is it more likely to be on? Right

Medications for treating hyperthyroidism? How do they work? PTU (propylthiouracil) Inhibit peroxidases, preventing DIT & MIT coupling Inhibits peripheral conversion of T4 to T3 Methimazole Methimazole has longer half life, PTU is less likely to cross placenta

Most common cause of hypothyroidism? Hashimoto’s thyroiditis Path: lymphocytic infiltrate Enlarged, painless, chronic thyroiditis

Most common thyroid cancer? Papillary Least aggressive, slow growing, best prognosis Path: psammoma bodies, orphan annie nuclei

Thyroid cancer with hematogenous spread? Follicular Spread to bone most common More aggressive than papillary

Thyroid cancer associated with MEN? Medullary Arise from parafollicular cells Path: amyloid deposition Gastrin causes increased calcitonin in medullary thyroid cancer

Treatment for medullary thyroid cancer? Total thyroidectomy with central neck dissection Monitor disease recurrence with calcitonin Clinically + lymph nodes – B/L MRND MEN – proph thyroidectomy & central neck by age 2

Thyroid cancer with worst prognosis? Anaplastic If resectable, do total thyroidectomy

Treatment for papillary thyroid cancer? <1cm – lobectomy >1cm – total thyroidectomy Special circumstances: Bilateral lesions, multicentricity, history of XRT, positive margins Total thyroidectomy I-131 – metastatic disease, residual local disease, +lymph nodes, capsular invasion

Treatment for follicular thyroid cancer? <1cm – lobectomy >1cm – total thyroidectomy I-131 for >1cm, extrathyroidal disease

Embryologic origin of parathyroids? Superior parathyroids 4th branchial pouch Inferior parathyroids 3rd branchial pouch

Blood supply to parathyroids? Inferior thyroid artery

Is PTH high or low in… primary hyperparathyroidism Is PTH high or low in… primary hyperparathyroidism? secondary hyperparthyroidism? tertiary hyperparathyroidism? Primary High Secondary Low Tertiary

Treatment of parathyroid cancer? En bloc resection – parathyroidectomy & ipsilateral thyroidectomy

Which adrenal vein goes directly into IVC? Right adrenal vein

In pheochromocytoma, what drug should be given preoperatively? Phenoxybenzamine Alpha blocker Do not give beta blocker before alpha blocker  hypertensive crisis

What is produced by parafollicular cells? Calcitonin

What is the most sensitive indicator of thyroid function? TSH

What is the function of the recurrent laryngeal nerve? Motor to all muscle of larynx except cricopharyngeus

What is the most common cause of hypercortisolism? Iatrogenic

What is the most common endogenous (non-iatrogenic) cause of hypercortisolism? Pituitary adenoma

What lab values are seen with primary hyperaldosteronism? Serum K low, urine K high Serum Na high Plasma renin low Aldosterone:renin >20

What is the treatment for adrenocortical carcinoma? Radical adrenalectomy Residual or recurrent disease Mitotane – treats endocrine symptoms, has caused tumor regression in some

What is the rate limiting step in catecholamine production? Tyrosine hydroxylase

What is the Rule of 10s? Pheochromocytoma 10% malignant 10% bilateral 10% familial 10% extra-adrenal 10% in children

What is MEN-1? Parathyroid hyperplasia Pancreatic islet cell tumor Pituitary adenoma

What is the most common pancreatic islet cell tumor in MEN-1? Gastrinoma

What is the most common pancreatic islet cell tumor overall? Insulinoma

What do you fix first in MEN-1? Parathyroid disease

What is MEN-2A? Parathyroid hyperplasia Pheochromocytoma Medullary thyroid cancer

What is MEN-2B? Pheochromocytoma Medullary thyroid cancer Mucosal neuromas Marfanoid body habitus

What do you fix first in MEN-2A and 2B? Pheochromocytoma

What gene mutation is associated with MEN-1? MENIN gene

What gene mutation is associated with MEN-2? RET proto-oncogene

What labs values are seen with Familial Hypercalcemic Hypocaliuria? High serum Ca, low urine Ca Urine Ca should be high in hyperparathyroidism Normal PTH Caused by defect in PTH receptor in distal convoluted tubule causing increased reabsorption of calcium

When do you do a parathyroidectomy for Familial Hypercalcemia Hypocalciuria? Never

What are the layers of the adrenal cortex & what is produced by each? Zona glomerulosa Mineralcorticoids (aldosterone) Zona fasciculata Glucocorticoids Zona reticularis Androgens/estrogens

What ezyme converts norepinephrine to epinephrine? Where is it found? PMNT Adrenal medulla and Organ of Zuckerkandl

The anatomic relationship of the parathyroid glands to the recurrent laryngeal nerve can be described as Both the superior & inferior glands are posterolateral to the nerve The superior glands are anteromedial and inferior glands are posterolateral to it Both the superior & inferior glands are anteromedial to the nerve The superior glands are posterolateral and inferior glands are anteromedial to it The superior glands are posteromedial and inferior glands are anterolateral to it

The anatomic relationship of the parathyroid glands to the recurrent laryngeal nerve can be described as Both the superior & inferior glands are posterolateral to the nerve The superior glands are anteromedial and inferior glands are posterolateral to it Both the superior & inferior glands are anteromedial to the nerve The superior glands are posterolateral and inferior glands are anteromedial to it The superior glands are posteromedial and inferior glands are anterolateral to it

A 63yo man has symptoms of Cushing’s syndrome A 63yo man has symptoms of Cushing’s syndrome. Labs show an elevated cortisol level with a slightly elevated plasma ACTH. A high dose dexamethasone suppression test shows suppression of ACTH and decreased cortisol. The condition most likely responsible is Adrenal carcinoma Pituitary adenoma Ectopic ACTH producing tumor Bilateral adrenal hyperplasia Adrenal adenoma

A 63yo man has symptoms of Cushing’s syndrome A 63yo man has symptoms of Cushing’s syndrome. Labs show an elevated cortisol level with a slightly elevated plasma ACTH. A high dose dexamethasone suppression test shows suppression of ACTH and decreased cortisol. The condition most likely responsible is Adrenal carcinoma Pituitary adenoma Ectopic ACTH producing tumor Bilateral adrenal hyperplasia Adrenal adenoma

Hypercortisolism – Causes Pituitary Adrenal – cancer, adenoma, hyperplasia Ecotopic ACTH producing tumor

Hypercortisolism Work-up 24hr urine cortisol Low-dose dexamethasone suppression test Suppression is normal Failure to suppress confirms Cushing’s syndrome ACTH measurement Is it ACTH dependent or independent? Low ACTH – suggests adrenal cause High ACTH – pituitary or ectopic ACTH producing tumor High-dose dexamethasone suppression test Suppression – suggests pituitary cause Failure to suppress suggests ectopic ACTH producing tumor CRH test Used if still can’t tell from above tests ACTH will increase with pituitary tumor, no change in ACTH in ectopic ACTH producing tumor

A patient with a 1cm medullary carcinoma of the right thyroid and no clinically significant adenopathy is best treated with Total thyroidectomy with central lymph node dissection Right thyroid lobectomy and isthmusectomy Total thyroidectomy Right thyroid lobectomy and subtotal left thyroidectomy

A patient with a 1cm medullary carcinoma of the right thyroid and no clinically significant adenopathy is best treated with Total thyroidectomy with central lymph node dissection Right thyroid lobectomy and isthmusectomy Total thyroidectomy Right thyroid lobectomy and subtotal left thyroidectomy MTC has high incidence of multicentricity, more aggressive course, & I-131 isn’t effective. For palpable lymph node in this case, do MRND.

What is the most common cause of congenital adrenal hyperplasia? 17-hydroxylase deficiency 21-hydroxylase deficiency 11-hydroxylase deficiency 18-hydroxylase deficiency

What is the most common cause of congenital adrenal hyperplasia? 17-hydroxylase deficiency 21-hydroxylase deficiency 11-hydroxylase deficiency 18-hydroxylase deficiency

21-hydroxylase

All of the following are direct effects of PTH except Stimulates absorption of calcium by the small intestine Stimulates resorption of calcium & phosphate from bone Stimulates reabsorption of calcium by the kidney Stimulates hydroxylation of 25-hydroxyvitamin D in the kidney

All of the following are direct effects of PTH except Stimulates absorption of calcium by the small intestine Stimulates resorption of calcium & phosphate from bone Stimulates reabsorption of calcium by the kidney Stimulates hydroxylation of 25-hydroxyvitamin D in the kidney

Effects of PTH Stimulates calcium reabsorption in the kidney (distal convoluted tubule) Activates osteoclasts  bone resorption  elevation of serum calcium Inhibits reabsorption of phosphate by the kidney Stimulates renal production of active vitamin D via 1- alpha-hydroxylase Indirect stimulation of calcium reabsorption from gut via actions of vitamin D

The most important test in the work-up of a solitary thyroid nodule is Sestamibi scan FNA Thyroid function tests CT scan Ultrasound

The most important test in the work-up of a solitary thyroid nodule is Sestamibi scan FNA Thyroid function tests CT scan Ultrasound

A 60yo woman presents with a history of kidney stones and serum calcium is 11. The most likely diagnosis is Parathyroid adenoma Parathyroid hyperplasia Parathyroid cancer Breast cancer with bone metastasis Secondary hyperparathyroidism

A 60yo woman presents with a history of kidney stones and serum calcium is 11. The most likely diagnosis is Parathyroid adenoma Parathyroid hyperplasia Parathyroid cancer Breast cancer with bone metastasis Secondary hyperparathyroidism

A 60yo woman presents with a history of kidney stones and a palpable neck mass. Her serum calcium is 14.1. The most likely diagnosis is Parathyroid adenoma Parathyroid hyperplasia Parathyroid cancer Breast cancer with bone metastasis Secondary hyperparathyroidism

A 60yo woman presents with a history of kidney stones and a palpable neck mass. Her serum calcium is 14.1. The most likely diagnosis is Parathyroid adenoma Parathyroid hyperplasia Parathyroid cancer Breast cancer with bone metastasis Secondary hyperparathyroidism

Dissection of the superior thyroid arteries during total thyroidectomy is most likely to result in which of the following complications? Aspiration Voice fatigue Hoarseness Stridor Loss of airway

Dissection of the superior thyroid arteries during total thyroidectomy is most likely to result in which of the following complications? Aspiration Voice fatigue Hoarseness Stridor Loss of airway

After total thyroidectomy for follicular thyroid cancer, the best test to monitor for recurrent disease is Serum calcitonin Ultrasound of the neck Serum thyroglobulin Serum TSH I-131 scan

After total thyroidectomy for follicular thyroid cancer, the best test to monitor for recurrent disease is Serum calcitonin Ultrasound of the neck Serum thyroglobulin Serum TSH I-131 scan

A 73yo woman with perforated diverticulitis s/p Hartmann’s procedure with sepsis develops increasing pressor requirements & you suspect adrenal insufficiency. What initial test can help you make the diagnosis? Cosyntropin stimulation test Serum cortisol 24hr urine cortisol Basic metabolic panel 24hr urine metanephrines

A 73yo woman with perforated diverticulitis s/p Hartmann’s procedure with sepsis develops increasing pressor requirements & you suspect adrenal insufficiency. What initial test can help you make the diagnosis? Cosyntropin stimulation test Serum cortisol 24hr urine cortisol Basic metabolic panel 24hr urine metanephrines BMP should reveal hyperkalemia, hyponatremia, hyperglycemia

Which of the following tests to evaluate for pheochromocytoma has the highest sensitivity? Plasma catecholamines Urine catecholamines Urinary total metanephrines Urinary VMA Urinary free metanephrines & normetanephrines 24hr urine cortisol

Which of the following tests to evaluate for pheochromocytoma has the highest sensitivity? Plasma catecholamines Urine catecholamines Urinary total metanephrines Urinary VMA Urinary free metanephrines & normetanephrines 24hr urine cortisol