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

Background: Leiomyosarcoma of the uterus has a high metastatic potential to distant sites due to its tendency for hematogenous spread. Case: 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. Conclusion: 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.