RESUMEN

This case report describes the presentation, diagnostic challenges, and management of a 64-year-old male with a malignant mesenchymal tumor presenting as a swelling in the anterior thigh. Despite initial misdiagnosis and treatment at a local hospital, the swelling worsened, leading to referral to a specialized hospital. Further investigations, including blood tests, ultrasonography (USG), and MRI, revealed a large solid cystic lesion compressing adjacent muscles, indicative of soft tissue sarcoma (STS). A skin biopsy confirmed the diagnosis of a malignant mesenchymal tumor. The patient, also suffering from hypertension and diabetes mellitus, was subsequently referred to the oncology department for further management. This case underscores the importance of thorough evaluation and histopathological confirmation for accurate diagnosis and management of STS, particularly in the context of atypical presentations and comorbidities.