Endocrine Abstracts

Introduction: Pituitary adenomas (PAs) account for <3% of all paediatric supratentorial tumours. Despite being benign, they can cause significant tumour- and treatment-related neuroendocrine and visual morbidity. Patients may be the index case for syndromes such as multiple endocrine neoplasia type 1 (MEN1).

Case report: Patient R was referred at 11.9 years with longstanding headaches and bilateral visual deterioration to the point of near-blindness. MRI revealed a large supra-intrasellar tumour causing third ventricular compression. Emergency debulking was initially scheduled for a suspected craniopharyngioma to preserve remaining vision. However, pre-treatment biochemistry revealed severe hyperprolactinaemia (PRL 23723 mU/l) alongside GH and TSH deficiencies. Surgery was deferred in favour of cabergoline therapy with an initial brisk response (PRL nadir 1993 mU/l) after a dose of 250 μg/week.

Unfortunately, despite escalating doses to 7 mg/week, his tumour demonstrated continued biochemical escape with radiological progression, requiring two partial resections (histology confirming a macroprolactinoma) and adjuvant proton beam radiotherapy. He suffered a post-operative stroke following his second operation and is now completely blind.

Initial questioning revealed only one paternal first cousin and one maternal first half-cousin (both once removed) with macroprolactinomas (i.e. no common ancestor). Patient R was positive for a functionally deleterious heterozygous MEN1 splicing mutation (c.784-9G>A). After multiple consultations, a history of multiple relatives with prolactinomas, hyperparathyroidism, and gastrinomas was revealed (the latter in a maternal grandaunt with a confirmed diagnosis of MEN1) within an inter-generationally multiply consanguineous family, with other members requiring screening.

Conclusions: This case demonstrates: i) the importance of excluding PAs by pre-treatment biochemistry as management differs from other suprasellar tumours, (ii) the difficulties in prioritising disease control against preservation of neuroendocrine and visual function without a clear evidence base, and (iii) the crucial need for a careful family history and universal genetic testing to identify the need for screening of relatives.