Diagnostic dilemma in an adolescent with a femoral mass

Javier Guzmán Carranza, Daniela Alejandra Pérez Díaz, E. G. González Salinas — Fri, 07 Mar 2025 00:00:00 -0700

This case involves a 16-year-old male adolescent who presented with intermittent pain in the left knee, worsened by physical activity and accompanied by persistent swelling. Despite initial treatment with analgesics and a splint, symptoms persisted, prompting an MRI that revealed a soft tissue mass in the distal third of the left thigh, compatible with parosteal osteosarcoma or pigmented villonodular synovitis. Subsequently, a surgical biopsy was performed to confirm the diagnosis. During the procedure, bone infiltration was observed, and the samples taken confirmed malignant osteosarcoma. The patient started chemotherapy under the EURAMOS protocol, achieving a significant tumor reduction of 60%.

This case highlights the importance of a multidisciplinary approach and precise differential diagnosis in young patients presenting with bone masses. The combination of imaging and biopsy was crucial in distinguishing between osteosarcoma and pigmented villonodular synovitis, two entities with very different treatments and prognoses. The case emphasizes the need to suspect malignancy in patients with persistent knee pain and swelling, even when a benign condition is initially considered. Rapid intervention and targeted treatment resulted in a favorable short-term response, underscoring the importance of early detection and management in the prognosis of these tumors. This case provides valuable insights into the management and diagnosis of bone lesions in adolescents.

Revista Bio Ciencias

Diagnostic dilemma in an adolescent with a femoral mass