gms | German Medical Science

Radiation induced sarcomas develop in 0.00035 to 0.2% of all radiated patients. The most common tumor entities are osteosarcomas, malignant fibrous histiocytomas, angiosarcomas as well as spindle cell sarcomas. Radiation induced leiomyosarcomas in the head and neck are extremely rare.

The 13 year old patient was diagnosed with a squamous cell carcinoma of the right tonsil in 1966. After resection, he underwent radiation therapy in the former Soviet Union (total dose of 101 Gy). In March 2003 he presented to our outpatient department with right sided oral pain. There was a tumor in the right tonsillar fossa with a diameter of 1.5 cm. Computed tomography showed the neoplasm to be well delimited from surrounding structures. There were no enlarged cervical lymph nodes and the staging did not show any distant metastases.

The tumor could be completely resected. Histopathologic and immunohistochemical examination revealed a leiomyosarcoma. The margins of resection were free of tumor. A panendoscopy three months after the resection with tissue sampling from the right tonsillar region did not show any signs of a tumor recurrence. The patient is followed up at our outpatient department every three months.

Leiomyosarcomas are neoplasms of mesenchymal origin deriving from smooth muscle tissue. They have to be differentiated from other spindle cell lesions such as spindle cell carcinomas, spindle cell myoepitheliomas, peripheral nerve sheath tumors, melanomas as well as myofibromas and angioleiomyomas. A complete resection represents the only curative treatment. Local and distant metastases of head and neck leiomyosarcomas are only occasionally encountered.

The case presented will highlight the clinical, radiological, histopathological as well as immunohistochemical characteristics of this extremely unusual radiation induced malignant tumor.