Endocrine Abstracts

A 61-year-old man presented to his primary care service with complains of frequent hot flushes, dizziness and headache. Following initial screening, an incidental pituitary lesion was diagnosed on computed tomography (CT) scan and hence was referred to specialist review. Further detailed history revealed similar presentation with dizziness and hot flushes two and a half years ago. He was then diagnosed with essential hypertension after a negative work-up for Cushing disease. He did not have any other co-morbidities and no family history of endocrinopathy.

Clinical examination was essentially unremarkable with intact visual fields. Pituitary function test results showed unusually high follicular stimulating hormone (FSH) (>200 IU/L) and moderately raised prolactin (700 mU/L). Serum testosterone was normal (7.3 nmol/L). Magnetic resonance imaging (MRI) scan showed large pituitary adenoma with right cavernous sinus involvement.

Following multi-disciplinary team discussion, the patient underwent elective trans-sphenoidal debulking resection of pituitary adenoma due to concerns about the size of the tumour and uncertainty of the nature of lesion. Histopathology confirmed the tumour to be a FSH secreting pituitary adenoma. Patient had residual adenoma despite the surgery and his FSH remained high (187.5 IU/L) post-surgery. The patient was then trialled with octreotide. Although the first trial of subcutaneous octreotide failed to lower FSH (>200I U/L), we saw good response with continued monthly treatment. His FSH levels normalised (11.2 IU/L) and his residual rumour shrunk. On his latest follow-up, patient continues to enjoy the period of symptom resolution and good health.

On reviewing the literature, we found limited reports of FSH secreting pituitary adenoma with fewer reports of successful resolution. We hereby report one such case which showed good response to treatment with octreotide.