Spindle cell oncocytoma of the adenohypophysis: 2 case reports of unusual radiological and intra-operative findings

•Spindle cell oncocytoma (SCO) is a rare primary tumour of the pituitary gland with only 26 cases reported in the literature to date.•Here 2 further cases are presented which showed iso-intensity and well circumcised shape on T2w MR images preoperatively.•During resection both cases had a firm, solid consistency like meningioma with greyish colour.•SCO might be suspected preoperatively if an iso-intense and well delineated pituitary mass is identified on T2w sequence.

BackgroundSpindle cell oncocytoma (SCO) is a rare primary tumour of the pituitary gland, recently designated as a separate entity from pituitary adenomas. Although our knowledge of pathological features of this tumour is growing in the light of recent reports, its radiological and surgical features are relatively unknown.Clinical presentationWe report two cases of SCO resected through a trans‑nasal trans‑sphenoidal approach. Both these cases showed isointensity and well circumcised shape on T2w MR images preoperatively. During resection both cases had a firm, solid consistency. Complete resection was not possible in order to avoid damage to the optic chiasm, and one case showed re-growth at follow-up and required further surgery.ConclusionSCO is a rare entity, difficult to identify on clinical basis alone, but with different radiological and surgical operative features compared to typical pituitary adenomas. This tumour should be suspected preoperatively if an isointense and well delineated pituitary mass is identified, or unusually during resection when a hard consistency is noted.