LAUSR

Introduction: Oral metastases are rare; nevertheless, they must be considered in the differential diagnosis of lesions in patients with a previous history of malignancy or older adults. The clinical signs of oral metastasis typically comprise pain, dysphagia, ulceration, bleeding, and paresthesia. Soft tissue sarcomas tend to affect the extremities and retroperitoneum. The most common metastases in the oral cavity are carcinomas, and sarcomas rarely metastasize to this area. Undifferentiated pleomorphic sarcoma (UPS) is a mesenchymal malignancy that infrequently affects the head and neck site. It shows a male predilection and occurs in all age groups. The lung is the most common area of distant metastasis in undifferentiated pleomorphic sarcoma. Case Report: This report presents a 61-year-old female patient with a painful bluish-purple mass of the posterior right mandibular alveolar mucosa. She had a history of thigh UPS about four years ago. An incisional biopsy was performed, and the specimen was stained with hematoxylin and eosin. Immunohistochemical antibodies for CK, S100, desmin, myogenin, MDM2, SOX10, and caldesmon were negative and focally positive for CD68. Ki-67 index was about 70%. Conclusions: This report aimed to increase awareness of a rare lesion by describing the clinical, histopathologic, and immunohistochemical findings of metastatic undifferentiated pleomorphic sarcoma of the oral cavity.