Malignant fibrous histiocytoma of the head and neck after radiation for squamous cell carcinoma.

A 60-year-old man presented with malignant fibrous histiocytoma of the oropharynx. The mass extended into the nasopharynx and larynx and caused severe upper airway obstruction that required emergency tracheotomy. Ten years earlier, he had undergone a right partial glossectomy and segmental mandibulectomy for squamous cell carcinoma of the right tongue base,followed by 50 Gy of radiation delivered over 33 sessions. The tumor was so aggressive that changes in its volume were visually distinguishable during physical examination over a 2-week hospital stay. Histologic evaluation revealed 7 mitotic figures per high-power field. Although radiation-induced malignant fibrous histiocytoma is rare in the head and neck, the recent medical literature indicates that its incidence is rising. This rise has been attributed to the increased effectiveness of head and neck cancer therapy, which results in prolonging patients' survival and, hence, their risk of subsequent disease. Because malignant fibrous histiocytoma is a late complication of radiation therapy, appearing on average 10 years following treatment, it is important that physicians who treat head and neck cancer monitor these patients over the long term and remain alert for its appearance, even despite the apparent "cure" of their original neoplasm.