A. Gilis-Januszewskaa (Prof), A. Boguslawska*a (Dr), M. Godlewskaa (Dr), ł. Kluczyńskia (Dr), M. Minasyana (Dr), A. Hubalewska-Dydejczyka (Prof)

a Chair and Department of Endocrinology, Jagiellonian University, Medical College, Cracow, Poland, Cracow, POLAND

* boguslawskaania@gmail.com

Giant prolactinomas constitute 2-3% of all lactotroph PitNETs with male preponderance. We present five male patients with giant prolactinomas with various clinical presentations. Case 1:A 66-year-old male was hospitalized due to left peripheral facial palsy. In computer tomography (CT) pituitary mass(41x43x64mm) invading cavernous/sphenoid sinuses/carotid arteries/optic chiasm was visualized. Bitemporal hemianopia/headaches/decreased libido were observed. Prolactin level was 22083 uIU/ml(N: 86-324uIU/ml). Cabergoline (1mg/week) was implemented. After 3 months, regression of pituitary tumor by 14mm and normal range prolactin level were observed. Milder headaches and improvement of vision were reported. Case 2:A 62-year-old male presented with life-threatening panhypopituitarism/diabetes insipidus at the age of 52. In MRI pituitary tumor 36x62x35mm with extrasellar extension/optic chiasm compression/ invading the third ventricle was found. Prolactin level 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 field deterioration was observed- patient consent to craniotomy. Histopathology revealed lactotroph-PitNET with Ki67>3%. After 6 months, tumor progression was noted. The patient was disqualified from radiotherapy. Temozolomide was introduced. After 9 cycles, regression of pituitary tumor was observed and decrease of prolactin level by 2600%. Case 3:A 56-year-old male was hospitalized due to syncope. In CT pituitary tumor 40x30mm was diagnosed with bitemporal hemianopsia. Prolactin level 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. Prolactin level was 21522uIU/ml. Insufficiency of thyroid and gonadal axis was diagnosed. Cabergoline was implemented (4mg/week) with regression of the tumor, decrease of prolactin level (8400uIU/ml), and complete remission of headaches. Case 5:A 67-year-old male was diagnosed with a pituitary tumor (65x35x40mm) at the age of 50 years. Due to hyperprolactinemia, cabergoline was implemented (7mg/week). After a few weeks, pituitary apoplexy occurred. Patient underwent emergency neurosurgery. MRI over the next 20 years demonstrated a stable residual tumour (22x28x11mm).The management of giant prolactinomas in men is challenging. Studies on prognostic factors for the efficient treatment of prolactinomas are needed.

The author has declared no conflict of interest.