Sinonasal Malignant Triton Tumor: A Case Report with Historical and Surgical Review

Diagnosis of malignant peripheral nerve sheath tumors (MPNST) remains a challenge due to its rarity, morphologic similarities with other sarcomas, and paucity of specific immunohistochemical markers. MPNST associated with skeletal muscle differentiation are termed “malignant triton tumor” (MTT). This manuscript reviews sinonasal malignant triton lesions. A 26 year-old female presenting with unilateral nasal obstruction was found on imaging to have opacification of the left nasal passage and sinuses due to assumed nasal polyps. A nasal polypectomy was performed. Pathological examination confirmed a nerve sheath tumor with skeletal differentiation in keeping with MTT. A completion radical resection was undertaken. A comprehensive meta-analysis of all MTT cases in the published English literature was undertaken with a focused review on sinonasal MTTs. MTT is uncommon in the nasal sinuses. Pathological evaluation with immunohistochemistry is the diagnostic tool for differentiating malignant Triton tumors from routine MPNSTs. Early and accurate diagnosis is critical in best patient management as complete tumor resection with negative surgical margins improves patient survival.