Paraspinal hibernoma: Grand Round presentation of a rare benign adipocytic tumor.

INTRODUCTION: We report an uncommon case of paraspinal hibernoma with a T12-L1 foraminal extension and discuss the potential differential diagnoses of paraspinal adipocytic tumors.

MATERIALS AND METHODS: A 32-year-old woman consulted our department with a right subscapular and paraspinal mass. There was no associated neurological deficit. The MRI revealed a paraspinal adipocytic tumor with a T12-L1 right foraminal extension. Percutaneous biopsy suggested a diagnosis of hibernoma.

RESULTS: Hibernoma is a rare and benign adipocytic tumor arising from embryologic remnants of brown fat. Specific MRI findings are discussed to differentiate hibernoma from other soft-tissue tumors. A planned marginal resection was undertaken with the final histopathology confirming the diagnosis of hibernoma.

CONCLUSION: Based on the Grand Round case and relevant literature, we discuss a rare case of paraspinal hibernoma with a foraminal component and no recurrence at 3-year follow-up.