Abstract
THE RATIONALE: Undifferentiated pleomorphic sarcoma originally known as malignant fibrous histiocytoma was declassified by the World Health Organization in 2002 as a formal diagnostic entity and renamed as an undifferentiated pleomorphic sarcoma. It accounts for <1% of malignant tumours of the long bone. PATIENT CONCERNS: A 33-year-old male patient reported with swelling and pain in the lower left posterior jaw region for 3 months with a history of fall on the floor 3 months back. DIAGNOSIS: On examination, diffuse solitary swelling was present on the left lower third of the face and was diagnosed radiographically and histopathologically as undifferentiated pleomorphic sarcoma of the mandible. TREATMENT AND OUTCOMES: Selective neck dissection, followed by reconstruction with fibula osteomyocutaneous flap and then referred for adjuvant radiotherapy. TAKE-AWAY LESSONS: Vimentin staining plays a substantial role in the diagnosis of undifferentiated pleomorphic sarcoma. A long-term follow-up after treatment is required to increase the chances of disease-free survival for the patients.