FRI320 The Various Clinical Outcomes Of Giant Prolactinomas In Men

Abstract Disclosure: A. Gilis-Januszewska: None. A. Bogusławska: None. M. Godlewska: None. &. Kluczyński: None. E. Rzepka: None. A. Hubalewska-D: None. Giant prolactinomas constitute 2-3% of all lactotroph PitNETs with male preponderance. We present a case series of giant prolactinomas with various clinical presentation. Case 1: A 66-year-old male hospitalized due to left peripheral facial palsy. In computer tomography (CT) pituitary mass (41x43x64mm) invading cavernous/sphenoid sinuses/optic chiasm was visualized. Bitemporal hemianopia/headaches were observed. Prolactin level (PRL) was 22083 uIU/ml(N: 86-324uIU/ml). Cabergoline (1mg/week) was implemented. After 3 months, regression of PitNET by 14mm and normoprolactinemia were observed. Milder headaches and improvement of visual field were reported. Case 2: A 62-year-old male presented with panhypopituitarism/diabetes insipidus at the age of 52. In MRI PitNET 36x62x35mm with extrasellar extension/ invading third ventricle was found. PRL was 223549uIU/ml. Despite dopamine agonist treatment progression of pituitary tumor/high prolactin level were observed-patient did not consent to neurosurgery. In 2019, significant visual filed deterioration was observed- patient consent to craniotomy. Histopathology revealed lactotroph-PitNET with Ki67>3%. After 6 months, tumor progression was noted. Patient was disqualified from radiotherapy. Temozolomide was introduced. After 9 cycles, regression of PitNET was observed and decrease of PRL by 2600%. Case 3: A 56-year-old male was hospitalized due to syncope. In CT pituitary tumor 40x30mm was diagnosed with bitemporal hemianopsia. PRL was 10446uIU/ml. Cabergoline(1mg/week) was implemented. After 3 months, regression of pituitary tumor/normal prolactin level/improvement of vision were noted. Case 4: A 23-year-old male presented with severe headaches and visual impairment at the age of 21. In MRI pituitary mass 52x52x41mm with extrasellar extension was found. PRL was 21522uIU/ml. Insufficiency of thyroid and gonadal axis was diagnosed. Cabergoline was implemented (4mg/week) with regression of the tumor, decrease of PRL (8400uIU/ml) and complete remission of headaches. Case 5: A 67-year-old male diagnosed with a PitNET (65x35x40mm) at the age of 50 years. Due to hyperprolactinemia, cabergoline was implemented (7mg/week). After few weeks, pituitary apoplexy occurred. Patient underwent emergency neurosurgery. MRI over next 20 years demonstrated stable residual tumor (22x28x11mm). Case 6: A 47-year-old male admitted to Emergency Unit due to severe headache. MRI showed PitNET (56x70x67mm). PRL was 22083 uIU/ml and plurihormonal pituitary insufficiency was observed. Cabergoline 2mg/week was implemented. After 3 months of treatment tumors regression was observed (56x68x50 mm) with normoprolactinemia. The management of giant prolactionomas in men is challenging. Further multicenter studies to understand the pathophysiology and prognostic factors of giant prolactionomas in men are needed. Presentation: Friday, June 16, 2023