General Medical Information

Pituitary Adenoma

Frank E. Lucente
Samir Shah
Roger Kula

Pituitary adenoma can be classified as functional (secreting) or nonfunctional (nonsecreting). Prolactinoma is the most common pituitary tumor and occurs most frequently among young women. Symptoms are galactorrhea with or without amenorrhea. Most patients respond to medical treatment with bromocriptine. Growth hormone adenoma causes gigantism among children before closure of the epiphyses of the long bones. Adults have acromegaly and enlargement of the jaw, hands, and feet. Other signs are hyperhidrosis, hypertrichosis, diabetes, cardiac disease, and paresthesia, such as carpal tunnel syndrome.

Corticotropin-secreting tumors manifest as Cushing disease, which is characterized by truncal obesity, moon facies, buffalo hump, pigmented stretch marks, hypertension, and hirsutism. The lesions usually manifest as microadenomas. Nelson syndrome, hyperpigmentation, and increasing sellar size can occur after bilateral adrenalectomy for corticotropin-secreting tumors. In these patients, the tumors are large and aggressive.

Nonfunctional pituitary tumors manifest as decreased hormonal function or without endocrine deficiencies. Patients often have panhypopituitarism with visual symptoms. The patient may have increased intracranial pressure or extraocular muscle palsy. The visual symptoms are caused by suprasellar extension of the adenoma, which affects the optic chiasm. This causes bitemporal hemianopia and progressive loss of visual acuity. Extraocular muscle palsy is caused by lateral extension of the tumor toward the cavernous sinus.