Post-radiation primary intranodal leiomyosarcoma.

An unusual case of post-radiation primary intranodal leiomyosarcoma of the cervical lymph node is presented. The patient was a 32-year-old white man who was treated in 1986 with hemiglossectomy and right neck dissection, followed by radiation therapy, for squamous cell carcinoma of the tongue. Six years later, he presented with an enlarged left cervical lymph node which on biopsy showed a high grade spindle cell malignant neoplasm. Immunohistochemistry and electron microscopic study verified the smooth muscle origin of the tumour. Extensive work-up for a second primary lesion was negative. Primary intranodal leiomyosarcoma is extremely rare. We briefly discuss the histological differential diagnosis of spindle cell lesions of lymph nodes, leiomyosarcoma of the vessel wall and radiation-associated sarcoma.