Case reportMultiple recurrences require long-term follow-up in patients diagnosed with spindle cell oncocytoma of the sella turcica

•Spindle cell oncocytoma of the adenohypophysis are prone to recur.•Spindle cell oncocytomas may remain dormant for several years prior to relapse.•Most effective approach in preventing recurrence is maximal safe surgical resection.

Spindle cell oncocytoma (SCO) of the sella turcica is characterized as a WHO grade I non-endocrine neoplasm of the sella turcica. Histologically, these tumors contain spindled and variably oncocytic cellular processes. Although SCOs lack immunoreactivity for neuroendocrine markers and pituitary hormones, they are clinically indistinguishable from non-functioning pituitary adenomas. In contrast to the initially described benign clinical course, several reports have subsequently illustrated cases with multiple recurrences with or without histological features of anaplasia in the form of nuclear pleomorphism, frequent mitoses, high Ki-67 index, and/or necrosis. With a follow-up of 14 years, we report a case of SCO with multiple recurrences along with an exhaustive clinico-pathological review of all 41 cases of SCO reported in the literature, of which recurrence has been described in 11 cases. Collectively, this report highlights the importance of long-term follow-up and the possible need for adjuvant radiotherapy in patients diagnosed with a sellar SCO and provides a comprehensive review of this rare nonadenomatous sellar tumor.