Endocrine Abstracts

Introduction: Giant prolactinomas are rare pituitary tumours. They can present with visual field defect, intracranial pressure symptoms and even temporal lobe epilepsy. Impairment of higher cognitive functions has been reported postoperatively after trans-cranial surgery and following radiotherapy. Reversible cognitive disturbances have been previously reported in patients with surgically decompressed arachnoid cysts but not after medical treatment of giant prolactinoma. We present a case of giant prolactinoma with successful restoration of severely impaired cognitive function with medical treatment alone.

Case report: A 22-year-old university student presented with gradually progressive short memory deterioration over a year and unprecedented poor academic performance. To compensate for it patient started using smartphone messages. Subsequently he was receiving multiple reminders which he could not recall. This unexplained rapid mental decline prompted urgent MRI which showed 48×52×28 mm mixed solid/cystic sellar mass with extrasellar and cavernous sinus extension and chiasmal distortion. Retrospectively he reported erectile dysfunction, but no galactorrhoea. He was hypogonadal with gynaecomastia. His testes were soft ~20 ml. Humphrey’s perimetry showed left superior quadrantanopia, visual acuity was normal. Anterior pituitary function revealed hyperprolactinaemia 515.217 mIU/l (0–450), central hypogonadism, normal thyroid, adrenal and somatotroph axes. He was commenced on cabergoline 250 μg/day. Within a week prolactin levels reduced by ~90% (56.061 mIU/l). Three months later MRI showed dramatic tumour shrinkage. Psychometric reassessment showed complete resolution of cognitive dysfunction. Patient has since successfully resumed his master in mathematics course.

Conclusion: Reversible dyscognition with severe short-term memory loss and personality disorders were reported in patients with surgically decompressed extracerebral cysts. Cystic giant prolactinomas can masquerade other intracranial malignancies but surgical intervention should be avoided. Dopamine agonists remains first line treatment obviating risks of pituitary surgery. This case highlights effectiveness of medical management in giant prolactinoma and is the first to report dramatic resolution of debilitating cognitive impairment.