Metastatic uterine leiomyosarcoma presenting as a primary sarcoma of the parotid gland.

Abstract

Leiomyosarcoma of the uterus has a high metastatic potential to distant sites due to its tendency for hematogenous spread. A 49-year-old woman presented with an enlarging parotid mass, diagnosed originally as a primary fibrosarcoma. Six years later, she developed pulmonary metastases and heavy, abnormal uterine bleeding. At hysterectomy, a uterine leiomyosarcoma, identical morphologically to the previous lesions, was identified. All tumors showed similar immunohistochemical staining, suggesting the metastatic nature of the original parotid tumor. This rare case of uterine leiomyosarcoma, presenting as a primary parotid sarcoma, underscores the importance of considering the possibility of a uterine primary tumor when a sarcoma arises in an organ in which these tumors are unusual.