Science and Education Publishing American Journal of Medical Case Reports 2374-216X 3 12 2015 11 18 Giant Prolactinoma: Case Report and Review of Literature 399 402 EN Khalid S.Aljabri Department of Endocrinology, King Fahad Armed Forces Hospital, Jeddah, Kingdom of Saudi Arabia Samia A. Bokhari Ahmad Akl AJMCR20153124 10.12691/ajmcr-3-12-4 2015 6 22 2015 9 6 2015 11 16 Prolactin (PRL) secreting adenomas are the most common secreting pituitary tumors, accounting for approximately 45% of all pituitary tumours. Giant prolactinomas are a rare subset of macroadenomas, characterized by large size (more than 40 mm in diameter (an arbitrary size), high aggressiveness and massive extrasellar involvement. We describe an unusual giant prolactin producing macroadenoma of pituitary gland in female patients with type 2 diabetes mellitus and its response to cabergoline.