<aside>

Pituitary adenomas are benign tumors arising from the anterior pituitary (adenohypophysis). They may be functioning (hormone-secreting) or non-functioning (silent) and are the most common type of sellar mass in adults.

</aside>

Epidemiology:

Account for 10–15% of all intracranial tumors
Peak incidence: 30–50 years
Equal sex distribution overall; prolactinomas more common in women
Often discovered incidentally on imaging (incidentalomas)

Classification

1. By Size:

Type	Size
Microadenoma	<10 mm
Macroadenoma	≥10 mm
Giant adenoma	≥40 mm

2. By Function:

Type	Hormone secreted	Clinical Syndrome
Prolactinoma	Prolactin	Galactorrhea, amenorrhea, infertility
Somatotroph adenoma	Growth hormone (GH)	Acromegaly (adults), Gigantism (children)
Corticotroph adenoma	ACTH	Cushing disease
Thyrotroph adenoma	TSH	Secondary hyperthyroidism
Gonadotroph adenoma	LH/FSH	Usually non-functioning
Non-functioning	None or silent hormones	Mass effect symptoms only

Variants & Aggressive Adenomas:

Plurihormonal adenomas
Silent corticotroph adenomas
Pituitary carcinoma (very rare; defined by CSF/metastatic spread)

Epidemiology:

Classification

1. By Size:

2. By Function:

Etiopathogenesis