Spindle cell oncocytoma in sellar region

Abstract

Objective To study the clinical manifestations, imaging and pathological features, diagnosis and differential diagnosis of spindle cell oncocytoma. Methods and Results A 59-year-old man presented with one year history of blurred vision, lags in response and fatiguability. Head MRI showed a mass at the sellar region. Histological examination showed the tumor was mainly composed of spindle cells arranged in fascicularis or irregularity with abundant eosinophilic granular cytoplasm and oval or short spindle nuclei without typical mitotic activity. Infiltration of scattered lymphocytes was observed in the stroma. Immunohistochemical staining showed partial tumor cells were immunoreactive to thyroid transcription factor-1 (TTF-1) in nuclei, anti-mitochondria antibody (AMA), S-100 protein (S-100), Galectin-3 and vimentin (Vim) in cytoplasm. Ki-67 labeling index was 3%. The final diagnosis was spindle cell oncocytoma in sellar region. The patient presented rapid loss of vision 2 months after surgery. Reexamined MRI showed a mass at the sellar region, and the patient was treated by radiotherapy. During the 10-month follow-up, the vision was not recovered, and the tumor was still existed. Conclusions Spindle cell oncocytoma is a rare benign tumor in the sellar region, which is considered as WHO grade Ⅰ tumor. It should be considered in the differential diagnosis of various sellar region lesions. Complete removal of tumor is important to prevent tumor recurrence. For patients who achieved partial resection, postoperative adjuvant radiotherapy is necessary.

DOI: 10.3969/j.issn.1672-6731.2019.02.006