pituitary incidentaloma

Introduction

incidentally discovered pituitary adenoma by CT or MRI. (see pituitary adenoma)

Etiology

• most are benign, nonfunctional pituitary adenoma Epidemiolgy:
• at least 10% of adults have pituitary microadenomas, most often incidental findings of brain MRI
• median microadenoma size is 4 mm
• size remains unchanged in 44% of patients, increases in 28%, decreases in 19%, & increases but later decreases in 9% over the 5 years after discovery
• only 3 of 177 microadenomas increased in size to > 10 mm

Laboratory

• serum prolactin
• serum IGF-1
• serum cortisol (AM)

may be optional

• ADH (serum sodium, serum osmolality, urine sodium, urine osmolality)
• serum TSH with reflex free T4
• serum LH serum FSH, 8 AM serum testosterone (male) serum estradiol (female)

Radiology

• pituitary incidentaloma identified by CT or MRI of sella turcica

Differential diagnosis

• acromegaly
• Cushing's syndrome
• prolactinoma

Management

• evaluate for hypopituitarism
• treat underlying disorder
• neurosurgery consultation
  • visual field defects
  • oculomotor nerve palsies
  • optic chiasm compression
  • hormone hypersecretion
  • hypopituitarism
  • tumor growth

More general terms

• incidentaloma
• pituitary adenoma