Unique case of a amplified biphasic mesenchymal tumor of the orbit.

-altered mesenchymal tumors are an emerging entity in soft tissue pathology. In the head and neck region, they are most commonly in the tongue. Limited published data indicate a propensity for local recurrence, regional spread, and distant metastasis in both -rearranged and -amplified tumors. The purpose of this report is to present the rare case of a -amplified spindle cell tumor of the orbit and a focused review of the literature. A 54-year-old woman presented with proptosis, eye pain, and ocular motility restriction in the left eye. Imaging demonstrated a tumor occupying the superomedial intraconal orbit that was distinct from the extraocular muscles, optic nerve, and globe. The tumor was totally resected with a combined open transorbital and endoscopic, endonasal approach. Pathological analysis demonstrated a spindled and epithelioid mesenchymal tumor with diffuse nuclear expression. PCR-based, next*-generation sarcoma fusion panel was negative for fusions, including fusions; however, breaks apart fluorescence in situ hybridization (FISH), which can be used as a surrogate for alterations due to proximity to 12q13.3, showing amplification. Post-operatively, the patient had recovered visual acuity. She received adjuvant radiation therapy (60 Gy in 30 fractions). Surveillance for recurrence, regional spread, and distant metastasis has been negative at a 6-month follow-up. Ultimately, we report the first case of a -amplified mesenchymal neoplasm of the intraconal orbit managed with gross total resection via a combined approach followed by adjuvant radiation therapy.