Prolactinoma in a 40-Year-Old Woman

A 40-year-old woman with a history of amenorrhea complained of recent headaches and galactorrhea for the last 6 months. A neurologic work-up revealed bitemporal hemianopia, and a radiograph of the skull suggested an enlarged sella turcica. A large pituitary adenoma disclosed by an MRI and a serum prolactin level of 360 µg/L led to a diagnosis of prolactinoma.

Prolactinoma is the most common pituitary adenoma. A serum prolactin level above 200 µg/L usually indicates this type of secretory tumor. In addition to causing headaches and compromising other pituitary hormone secretion, these tumors may grow and compress adjacent cranial nerves and lead to neurologic dysfunction.

Drs Sonia Arunabh and Navin Verma of Flushing, NY, report that this patient responded to bromocriptine, 10 mg/d. Within a month, regular menstrual periods resumed, and the intensity of the headaches diminished. Radiotherapy or surgical resection may be considered for macroadenomas that do not respond to bromocriptine therapy.