Spindle cell oncocytoma with late recurrence and unique neuroimaging characteristics due to recurrent subclinical intratumoral bleeding

Abstract

Spindle cell oncocytoma (SCO) is a rare sellar-region tumor recently codified in the World Health Organization (WHO) 2007 Classification as a grade I neoplasm. Despite this grading, recurrences have been demonstrated but, to date, extensive recurrent bleeding into these tumors has not been documented. A 70-year-old woman first presented in 1996 with visual difficulties and was found to have a sellar-region mass with heterogeneous neuroimaging features, leading to preoperative diagnosis of craniopharyngioma. Transsphenoidal, gross total resection was achieved despite extensive intraoperative bleeding; pathology showed an unusual spindle cell neoplasm which could not be further classified. She received no further treatment and was lost to our follow-up until 2009, when she again presented with visual deterioration. Neuroimaging demonstrated recurrence of a large sellar-region tumor with heterogeneous signal characteristics, prompting re-resection. Review of her original and recurrent tumor allowed diagnosis of SCO; extensive intratumoral hemorrhage of varying ages and widespread hemosiderin accounted for her complex neuroimaging features. Vimentin, S100, and galectin-3 immunoreactivity was consistent with SCO. EM demonstrated abundant mitochondria, short intercellular junctions, and absence of neurosecretory granules. Thyroid disease was documented clinically. SCOs are sufficiently rare that documentation of unusual features is important. Recurrent bleeding with resultant complex neuroimaging is unique to this case, but appears to overlap with a related sellar-region tumor, pituicytoma. The presence of thyroid disease also links SCO with pituicytoma. The 13-year interval to recurrence is the longest reported to date in SCO; WHO grade I designation may be premature for this neoplasm.