Causes of pituitary enlargement:

Pituitary adenoma: (anterior lobe) most important lesion / tumour of the pituitary…

• It is benign, rarely infiltrate locally and may be non-functional (majority) or functional.

• Found in up to 20% of population post-mortem and represents about 15% of all intracranial neoplasms.

Other neoplastic causes of pituitary enlargement:

• Atypical adenoma and carcinoma: (anterior pituitary) rare, usually non-functional

• Craniopharyngioma: above the sella turcica (Rathke’s pouch origin)

• Posterior pituitary neoplasm: commonest is glioma

• Secondary neoplasm: more common in posterior pituitary, may present as diabetes insipidus (breast and lung commonest primary sites)

Non-neoplastic causes of pituitary enlargement:

• Congenital adrenal hyperplasia

• Primary hypothyroidism

• Pituitary gland enlargement secondary to dural arteriovenous fistula in the cavernous sinus

• Pregnancy results in physiologic pituitary enlargement.

Category: Pathology Notes