Pleomorphic Leiomyosarcoma of the Nasopharynx and Oropharynx Presenting as a Benign-Appearing Pedunculated Mass.

Pleomorphic leiomyosarcoma is a rare malignant mesenchymal tumor, particularly in the head and neck region. The authors report a case of pleomorphic leiomyosarcoma involving the nasopharynx and oropharynx that presented as a well-circumscribed, benign-appearing pedunculated mass without overt invasive features on imaging. Despite its indolent clinical and radiologic appearance, histopathologic examination revealed a high-grade malignancy. The patient underwent surgical excision, and adjuvant radiotherapy was initiated but discontinued early because of treatment intolerance. The patient remains free of disease at 3-year follow-up. This case underscores a potential diagnostic pitfall: benign-appearing lesions in the upper aerodigestive tract may represent aggressive malignancies, and early tissue diagnosis is essential to enable timely oncologic management.