CRAN-28. A SINGLE CENTER EXPERIENCE OF MANAGING A SERIES OF CHILDHOOD MACROPROLACTINOMAS

Childhood prolactinomas often occur as aggressive macro (1-4cm) or giant (>4cm) tumours, with little consensus regarding timing of different therapies. AIM: To highlight the phenotype and the outcome of childhood macroprolactinomas. SUBJECTS AND Collected data from 10 children (<18 years) presenting to our centre between 2009–2017, with hyperprolactinaemia (>9000mU/L) due to macroprolactinomas. Age of symptoms onset was 8–15.8 years. Presenting symptoms included headaches (10/10), endocrinological signs (gynaecomastia, galactorrhoea, pubertal arrest, short stature,7/10) and visual deficit (3/10). The initial prolactin levels varied and reflected tumour’s size (9,176-1,238,960 mIU/L). At diagnosis, children had 1–4 pituitary hormone deficits, GH (7),TSH (6),LH/FSH (6) and ACTH (4).All patients had suprasellar extension and 9 had compromised cavernous sinus and optic pathway. All children had first-line cabergoline treatment apart from one misdiagnosed. Two patients required urgent transsphenoidal surgery for pituitary apoplexy and for CSF leak post cabergoline. Four patients experienced cabergoline side-effects (headaches, aggressive behavior, impulse control disorder). Five cases continue on dose-escalating cabergoline treatment. Five cases required surgery and one radiotherapy due to cabergoline side-effects(1), visual compromise(1)or tumour regrowth(2).One proved heterozygous for an MEN1 mutation. None harboured an AIP mutation. Cabergoline should be the first-line treatment in childhood-onset macroprolactinomas. Dose-escalation maybe is necessary for controlling disease, but needs monitoring of side-effects or complications. In resistant disease, surgery increases endocrine deficits and radiotherapy may be necessary. MEN1 and AIP analysis is strongly recommended to inform about pathogenesis, allow screening for other manifestations and to identify at-risk relatives.