Case report of pituitary spindle cell oncocytoma concurrent to growth-hormone secreting pituitary adenoma

Spindle cell oncocytomas (SCOs) are rare, benign, non-functioning tumours of the pituitary gland that were included in the World Health Organisation’s (WHO) classification of central nervous system tumours in 2007. Due to their radiological appearance, they often are mistaken for pituitary adenomas prior to histopathological confirmation. Due to their rarity, there are no known risk factors or correlations in the literature between SCOs and other primary central nervous system tumours.

This is a case report of a 71 year old gentleman who underwent transsphenoidal resection of a symptomatic and histologically-confirmed growth-hormone secreting pituitary adenoma. Due to persistently elevated IGF-1 levels, he underwent repeat surgery which led to biochemical remission. The histology from the second surgery returned a diagnosis of SCO. We hypothesise that our patient had concomitant pathologies of a GH-secreting adenoma and a SCO. This is the first described case of a synchronous functional pituitary macroadenoma and a spindle cell oncocytoma.