The Prevalence and Natural History of Pituitary Hemorrhage in Prolactinoma

Context: Incidental pituitary hemorrhage, without full pituitary apoplexy, is a recognized radiological finding, but little information exists on its clinical behavior, with most reports describing surgically treated macroprolactinoma or nonfunctioning adenoma.

Objective: Our aim was to characterize the prevalence, natural history, and risk factors associated with pituitary hemorrhage in a large clinic prolactinoma population.

Design: The design consisted of a retrospective analysis of a clinic population.

Setting: The setting was a tertiary endocrine center in a large teaching hospital.

Patients: We studied three hundred sixty-eight patients with prolactinoma. The presence of hemorrhage was documented on magnetic resonance imaging. Mainoutcome measure: The main outcome measures were the prevalence, risk factors, andnatural history of pituitary hemorrhage.

Results: Pituitary hemorrhage was found in 25 patients, giving an overall prevalence of 6.8%, and was significantly higher in macroprolactinoma (20.3%) compared to microprolactinoma (3.1%, P <.0001). Three patients had classical pituitary apoplexy. The majority of patients in the hemorrhage group had macroprolactinomas (16/25 [64%]) and were women (22/25 [88%]). The proportion of womenwith macroprolactinoma was higher in the hemorrhage group (14/16 macroprolactinomas [87.5%]) than in the nonhemorrhage group (36/63 macroprolactinomas [57.1%], P = .02). The majority of pituitary hemorrhages (92%) were treated conservatively with dopamine agonist therapy for hyperprolactinemia. Eighty-seven percent of patients had complete resolution of their hemorrhage within 26.6 +/- 23.3 (mean +/- SD) months. The presence of macroprolactinoma (odds ratio 9.00 [95% CI 3.79-23.88], P <.001) and being female (odds ratio 8.03 [95% confidence interval 1.22-52.95], P = .03) were independently associated with hemorrhage.

Conclusions: These data show that incidental hemorrhage in prolactinoma is not uncommon. It is more likely to occur in macroprolactinoma, where 1 in 5 develop hemorrhage, and is particularly common in women with macroprolactinoma. The majority are asymptomatic and resolve spontaneously.