Temporalis muscle metastasis of the uterine leiomyosarcoma: a case report.

Leiomyosarcomas are malignant tumors of smooth muscle origin. These tumors are very rare in the head and neck region. The majority of leiomyosarcomas of the head and neck arise in the paranasal sinuses, oral cavity, jaws and superficial soft tissues like the scalp. A mass was observed in the right temporoparietal region of the scalp of a 76-year-old female. Two years before presentation, the patient was operated for primary uterine leiomyosarcoma. Over the ensuing years, the mass substantially increased in size. Radiologic findings revealed a mixed density mass of the right temporalis muscle. Histologic and immunohistochemical examination of the tumor showed a malignant mesenchymal neoplasm consisting of spindle-shaped atypical mesenchymal cells with marked pleomorphism and central cigar shaped nuclei arranged in fascicles. We report a rare case of uterine leiomyosarcoma metastatic to the temporalis muscle, proven by histopathology.