A 37-year-old woman has presented with complaints of headache, amenorrhea and acromegaly.

Her laboratory studies showed markedly elevated levels of Insulin like Growth Factor 1 (IGF-1), and low levels of follicle-stimulating hormone and luteinizing hormone. Computerized tomography has revealed a pituitary tumor without extra-sellar extension. The tumor has completely excised via Endoscopic transsphenoidal approach. Histologically, the tumor has diagnosed as a pituitary neuroendocrine tumor with GH positive cells. The serum IGF1 levels have gradually decreased to the normal range and the patient was symptom free for three and a half years when she has returned with complaint of visual impairment. The brain MRI that time has shown a supra-sellar mass growing independently into the remaining sellar part. Subsequently, surgical operation has performed via trans-nasal endoscopic approach. Histopathological and immunohistochemistry examination have revealed a rare case of growth hormone producing pituitary neuroendocrine tumor with brain invasion and lymphocytic infiltration.

The aim of this publication was to present a rare case of growth hormone producing pituitary neuroendocrine tumor with brain invasion and lymphocytic infiltration ²⁾.