Analysis of clinical features and prognosis of malignant triton tumor: A report of two cases and literature review.

Malignant triton tumor (MTT) is a malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. The prognosis of patients is poor, and due to its rarity, large case studies are lacking. The aim of this study is to describe the clinical features and identify potential prognostic factors. Two patients with MTT in the head and neck treated at our department are reported. A literature search revealed another 198 published cases. All of these cases then went through a retrospective analysis. The ratio of male-to-female incidence was 1.5:1, and the median age at diagnosis was 29 years. In 41.7% of cases it occurred in patients with neurofibromatosis type 1. The five-year survival of MTT was found to be just 35%. Cox proportional hazards analysis revealed that complete resection (hazard ratio, 0.396; P=0.032) and metastases (hazard ratio, 3.188; P=0.004) were associated with mortality, indicating that complete resection may lead to a longer life span, and that the existence of metastasis suggested a worse prognosis for patients with MTT.