Unique case of a GLI1 amplified biphasic mesenchymal tumor of the orbit

• Published in: Orbit Vol. ahead-of-print; no. ahead-of-print; pp. 1 - 5
• Main Authors: Godse, NR, Alsulaimani, S, Singh, AD, Fletcher, CD, Astbury, C, Fritchie, K, Recinos, PF, Sindwani, R
• Format: Report
• Language: English
• Published: Taylor & Francis 23.06.2023
• Subjects: endoscopic endonasal surgery; GLI1 amplified tumor; multiport skull base surgery; orbital tumor
• ISSN: 0167-6830; 1744-5108
• DOI: 10.1080/01676830.2023.2225196

GLI1-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 GLI1-rearranged and GLI1-amplified tumors. The purpose of this report is to present the rare case of a GLI1-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 GLI1 expression. PCR-based, next*-generation sarcoma fusion panel was negative for GLI1 fusions, including GLI1::ACTB fusions; however, DDIT3 breaks apart fluorescence in situ hybridization (FISH), which can be used as a surrogate for GLI1 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 GLI1-amplified mesenchymal neoplasm of the intraconal orbit managed with gross total resection via a combined approach followed by adjuvant radiation therapy.