Invasive Giant Prolactinoma

A 64-year-old man presented with an 8-year history of decreased libido, impotence, and blurred vision. The neurologic examination revealed a mild left facial weakness, visual acuity of (20/60), and right homonymous hemianopia. Laboratory investigation of serum prolactin was 7896 ng/mL. Testosterone, free T4, and adrenocorticotropic hormone were all decreased. Brain magnetic resonance imaging showed a giant sellar/suprasellar lesion, compressing on the brainstem and extending to the cerebellopontine angle. A diagnosis of panhypopituitarism secondary to a giant macroprolactinoma was made. The patient was started on hormonal replacement therapy and underwent craniotomy and tumor resection. The histopathologic findings were compatible with prolactinoma. Invasive giant prolactinomas are defined as 1) tumor size of >4 cm in diameter; 2) serum prolactin of >1000 ng/mL; and 3) mass effect or hyperprolactinemia-induced symptomatology. The management of invasive giant prolactinoma commonly comprises a multimodal approach of both medical treatment and surgical intervention.