Internal Medicine

0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:57

Pituitary Tumors 1175

■Cushing’s disease: central obesity, emotional lability, hypertension,

diabetes mellitus; weakness, striae

■Acromegaly: enlarged hands and feet, sleep apnea, loose teeth, prog-

nathic jaw, frontal bossing, diabetes, carpal tunnel syndrome

■TSH-secreting tumor (rare): thyrotoxicosis

■LH/FSH-secreting tumor: asymptomatic; hypopituitarism

■Prolactinoma: galactorrhea, amenorrhea, impotence

■Diabetes insipidus: polydipsia, polyuria, nocturia

tests

Laboratory

■Basic blood studies:

➣LH, FSH, prolactin, free T4, TSH, testosterone, ACTH

➣Cortisol after Cosyntropin or insulin tolerance test

24-hour urine free cortisol

8:00 AM cortisol after 1 mg (low dose) or 8 mg (high dose)

dexamethasone at midnight

➣Insulin-like growth factor-I (IGF-I)

➣Growth hormone (GH)

➣Electrolytes, glucose

➣Urinalysis

■Ancillary blood tests:

➣Estradiol

➣ACE

Imaging

■MRI of pituitary and brain.

Pituitary tumors classified as macroadenomas (≥1 cm) or microadeno-

mas (<1 cm); microadenomas rarely grow on follow-up exams

differential diagnosis

■Pituitary tumor:

➣Nonsecretory, prolactinoma, acromegaly, Cushing syndrome

➣Usually causes partial or complete anterior pituitary insuffi-

ciency

➣Most common deficiencies: GH > LH, FSH > TSH, ACTH

■Enlarged pituitary without mass: lymphocytic hypophysitis, severe

primary hypothyroidism

■Aneurysm, meningioma

■Pituitary apoplexy

■Rathke pouch cyst