Endocrine Abstracts

A 36-year-old male presented to the emergency department with a 24-hour history of mutism, paranoia and 3-day history of social withdrawal. He was unable to engage with healthcare professionals and the history was elicited from his mother. Due to a background of mild depression, an acute psychotic diagnosis was initially pursued. A CT scan on admission revealed a large pituitary lesion. A pituitary MRI scan thereafter demonstrated a large 25 × 30 × 18 mm sellar and suprasellar pituitary macroadenoma involving the left cavernous sinus and internal carotid artery, protruding into the left cranial fossa and displacing the optic chiasm. Biochemical investigations revealed a serum prolactin level c.66.000 mIU/l with biochemical hypogonadism (testosterone 3.3 nmol/l, LH 1.7 IU/l). Clinical examination revealed no ophthalmoplegia nor visual field deficits. He was unable to engage with formal visual-field testing initially, however these later demonstrated a superior bilateral deficit. Capacity assessment on admission demonstrated a lack of mental capacity so a best interests decision for medical management was made jointly by Psychiatry and Endocrinology teams. He was commenced on the antidepressant sertraline and the antipsychotic aripiprazole (10 mg daily), a partial dopamine agonist. Aripiprazole was chosen to treat both hyperprolactinaemia and psychotic symptoms, whilst avoiding potential neuropsychiatric side effects of ergot-derived dopamine agonists. After two weeks of therapy, his prolactin fell to c.38.000 mIU/l and his mental status had improved. However, by two months, he reported weight gain, fatigue, leg cramping and stiffness, whilst blood tests showed a prolactin rise to c.55.000 mIU/l. At this point aripiprazole was not felt to be of any further benefit and was switched to cabergoline, initially 250 mg once weekly and quickly up-titrated to 500 mg twice weekly. By month six, his prolactin had fallen to c.3.500 mIU/l and his testosterone (9.8 nmol/l) and LH (0.8 IU/l) showed improvements. Repeat MR imaging demonstrated a reduction in macroadenoma size with decompression of the optic chiasm. Currently at month eight, his mood has normalised. His prolactin however has risen to c.4.500 mIU/l so cabergoline has been increased to 750 mg twice weekly. This case highlights the challenges presented by the combination of neuropsychiatric symptoms and a functioning macroprolactinoma. Initial medical management with aripiprazole monotherapy can be used to treat psychiatric disease without worsening prolactin levels. We have identified seven case reports published since 2007 of aripiprazole being used for patients with prolactinomas who have coexistent psychiatric symptoms [1–7]. These cases describe the use of dopamine agonists concomitantly or first, with aripiprazole to minimise the side effects.