ESPE Abstracts

Background: Prolactinomas are relatively rare during childhood, with an incidence of 0.1 per million. Children with hyperprolactinaemia have widely varied presentations depending on age, sex, and tumour size. Whilst adults typically present with galactorrhoea or hypogonadism, children tend to present with pubertal delay and growth issues.

Objective and hypotheses: Poorer surgical outcomes have been reported in children with macroprolactinomas compared to adults, leading to uncertainty regarding optimal treatment. The following outlines a case of macroprolactinoma in an adolescent.

Method: A 15.5-year-old male presented with concerns of slow pubertal progression. Examination showed 15 ml testes and early secondary sex characteristics. Baseline bloods showed measurable gonadotrophin levels and low testosterone. Clinical review following 6 months observation, showed interval growth deceleration and progression of testes to 20 ml without further secondary sex characteristic development. Repeat investigations revealed unchanged gonadotrophin and testosterone levels and markedly elevated serum prolactin (48 061 mU/l, reference range 100–420). The patient was otherwise asymptomatic of hyperprolactinaemia. Magnetic resonance imaging showed a large pituitary mass measuring 23×22×14 mm, with features consistent with macroprolactinoma. Extrasellar extension was present (optic nerve compression, cavernous sinus invasion, internal carotid artery displacement, and left posterior clinoid process erosion). Impressively there was no visual field defect on ophthalmological assessment. Dynamic endocrine testing revealed GH insufficiency and partial ACTH and gonadotrophin insufficiencies.

Results: Cabergoline was commenced and dose intermittently increased over 6 months. The prolactin level gradually decreased to 700 mU/l by 9 months post diagnosis. Additional management included testosterone and GH therapy and emergency glucocorticoids. Surgical intervention was deferred at presentation, in the absence of neurological signs.

Conclusion: This case demonstrates a cabergoline-responsive macroprolactinoma presenting with growth deceleration and an unusual pattern of pubertal arrest. It raises the controversial question of surgical intervention indications. In Australia it also raises the dilemma of GH access in the context of a pituitary tumour.