Endocrinology - 8%

Question 1

Hyperparathyroidism

Answer 1

Overactive parathyroid gland - secrete too much PTH = incr level of Ca

increase PTH => bone breakdown => Ca rise

Primary - d/t parathyroid adenoma

Secondary - physiologic resposnse to hypoCa or Vit D deficiency (MCC kidney disease)

Sxs: same as hypercalcemia

• bone loss (incr PTH and Ca abs from bones) = pain in bones
• renal loss of Ca = kidney stones
• incr GI abs of Ca = abd groans
• irritability, psychosis, depression = moans

Dx:

• Incr Ca, PTH, decr phosphorus
• urine - hyperphosphaturia, hypercalciuria

Tx:

• Primary = surgical resection, if all 4, remove 3.5 glands
• Secondary = replace cause (vit D/Ca supp)
• if Ca very high = IV fluids, Lasix, calcitonin
• tx osteoporosis with bisphosphonates

Question 2

Adrenal Carcinoma

Answer 2

Adrenal Cortical Cancer - rare, considered as ddx for any adrenal mass, esp > 4cm

usu incidental - 80% non functional adenomas; 15% functional (pheochromocytomas, aldosteronoma, cortisol producing adenomas)

Dx:

• Labs
  
  • Plasma fractionated metanephrines r/o pheochromo
  • 24 hr urinary free cortisol or dex suppress test
  • Serum K, aldosterone
  • DHEA-S = virilization/excess androgens
• CT >4cm, high attenuation, calcifications, central necrosis, irregular shape
• MRI to distinguish btwn adenoma, pheochromo, ACC

Tx

• Adrenalectomy - complete surgical excision w/ negative margins

Question 3

Hyperthyroidism

Answer 3

Production of too much thyroxin hormone - increase metabolism

Eti - MCC Grave’s disease (autoimmune), toxic adenoma, thyroiditis, pregnancy, amiodarone

Sxs:

• weight loss, anxiety
• warm, moist skin
• insomnia
• fine tremor, muscle cramp, hyperreflexia
• amenorrhea
• tachycardia/palpitations
• Graves - diffuse goiter w/ bruit, exopthalmos, pretibial myxedema
• heat Intolerance

Dx:

• TSH low and T4 high - primary disease
• TSH high and T4 high - secondary dz
• Anti-thyrotropin antibodies
• RA Iodine uptake = increased uptake in
  
  • Graves = diffusely high uptake
  • Toxic Multinodular goiter = Discrete areas of high uptake

Tx:

• BB symptomatic
• Methimazole
• Propylthiouracil (PTU) - safe for pregnancies in the first trimester, then switch to Methimazole
• Thyroidectomy - complication recurrent laryngeal

Question 4

Thyroid Carcinoma

Answer 4

MCC = radiation exposure

Papillary carcinoma is MC, thyroid adenoma MC benign nodule; young F 40-60

nodules must be >1cm to be palpated

Dx

• US - malignant if
  
  • microcalcifications, hypoechogenicity, Irregular nodule margins,
• lesions > 1 cm biopsied
• Thyroid uptake scan
  
  • ​cancerous lesion do NOT take up iodine “cold”
  • non-cancerous lesion will take up iodine “hot”
• FNA to culture

Question 5

Pheochromocytoma

Answer 5

Catecholamin secreting adrenal tumor - secretes NorEpi and Epi

a/w Neurofibromatosis Type 1, MEN 2A/2B

Sxs - 5Ps

• Pressure - HTN
• Pain - HA
• Perspiration - excessive sweating
• Palpitations
• Pallor

Dx

• 24 hr catecholamines w/ metabolites - metanephrine and vanillylmandelic acid
• MRI or CT of abd

Tx

• complete adrenalectomy
• a blockade - phenoxybenzamine or phentolamine x 7-14 d followed by BB for HTN control
  
  • do NOT give BB first = life threatening HTN

Question 6

Thyroid Nodules

Evaluation

Answer 6

1. Palpable nodule > 1cm
2. Confirm with US
3. if TSH low =>
   
   • Thyroid Radioiodine Uptake or Scintigraphy scan
     
     • malignant wont take up iodine = nonfunctional “cold”
     • Confirm with FNA
4. if TSH normal or high => FNA if
   
   • microcalc, irreg margins
   • next to recurrent laryngeal n. or LNs

Tx

• malignant- thyroidectomy
• benign - f/u in 6 mos
• unsatisfactory specimen - FNA repeat 1-4 wks to mirror structure

Question 7

Fatigue

Answer 7

six to 12 wks of fatigue not unusual during recovery from surgery

Ddx

• Hypothyroidism
• DM
• Pituitary insufficiency
• Hypercalcemia
• Adrenal insufficiency
• Chronic Renal or hepatic failure

Dx

• CBC - anemia
• ESR
• Chem panel
• TSH

Question 8

Palpitations

ddx

Answer 8

• Hyperthyroidism
• Pheochromocytoma
• Anxiety
• Structural Heart disease (CAD, CMO, Afib/flutter, AV stenosis, MV prolapse, SSS, WPW)
• Hypoglycemia
• Drugs - cocaine, amphetamines, caffeine

Dx

• Eletrophysiology for structural heart dz
• HP, EKG, echo, exercise testng
• CMP, CBC, TSH, U tox