Pituitary adenoma

Diagnosis:

Suggested by MRI and confirmed by pathology (brain biopsy/resection)

Clinical features:

  • Non-secreting tumors: present with visual field defects commonly bitemporal hemianopsia. Also present with headaches or are incidentally found
  • Hormonal syndromes with secreting tumors: amenorrhea and infertility with prolactinomas, acromegaly, Cushing’s disease with other hormones
  • Pituitary apoplexy: Severe headache, Sudden visual loss or sudden collapse, multiple ocular nerve plasies

Findings on Investigations:

Microadenoma: <10 mm.

MRI T1, hypointense, doesn’t enhance unlike normal pituitary.
CT. hypodense, erosion of sellar floor, upward convexity of diaphragm sellae,

MacroAdenoma :

>1 cm. Hemorrhage may occur, may invade cavernous sinus, extend into suprasellar space (Michellin Man appearance)
MRI:

  • T1, hypointense lesion, if present hypointense cysts
  • T2, if present hyperintense cysts

Pathology:

Histology:
Small round blue cells. Further classification based on other stains & immunohistochemistry.

Hormonal tests:

Raised prolactin: Prolactinoma or compression of the stalk. In prolactinoma, Prolactin >200 ng/ml
Insulin stimulation tests: hypopituitarism
OGTT with GH +clinical features: acromegaly
TSH secreting pituitary adenoma: high TSH, high free T4, high free T3. TRH sitimulation test: flat TSH response

Treatment:

Depends on presence & absence of hormonal secretion & neurological deficits
If nonsecreting:

  • Surgery:
    • Transfrontal or trasphenoidal approach, or subfrontal craniotomy if there is intracranial extension beyond the pituitary fossa
    • If +Hypohpysectomy: need hormonal & steroid replacement

Radiation therapy

Related articles: