Coincidence of Undifferentiated Pleomorphic Sarcoma and Epithelioid Leiomyosarcoma in a Patient; A Case Report

Introduction: Soft tissue sarcoma (STS) is a rare tumor with mesodermal origin. There are more than 100 different types of histology in sarcoma, which present different clinical behaviors. Liposarcoma, leiomyosarcoma, and undifferentiated pleomorphic sarcoma are among the most common pathologies Case Presentation: The patient was a 46-year-old man with 2 masses. The pathology of chest-wall mass (250 × 187 mm) was compatible with undifferentiated pleomorphic sarcoma (UPS). Arm mass (42 × 29 mm) pathology was suggestive of low-grade epithelioid leiomyosarcoma with smooth muscle differentiation. He received two cycles of mesna and doxorubicin and ifosfamide (MAI) regimen chemotherapy due to large and multiple masses, but the tumor size did not change. After consultation with an orthopedic oncosurgeon, wide masses resection was done. Adjuvant chemotherapy with an MAI regimen was continued for a total of 6 courses and radiation with a 60 Gy total dose to the posterior aspect of the chest wall. No recurrence or complications was observed after 4 months of follow-up. Conclusions: Multiple STS is rare; nevertheless, its probability, either synchronous or metachronous, should be considered during patient examine and follow-up. In the case of a secondary lesion, different histology is probable, and the patient should be biopsied and imaged.