Dedifferentiated Chondrosarcoma: A Report of a Rare and Intriguing Case.

Dedifferentiated chondrosarcomas (DDCS) are highly aggressive tumors with poor outcomes. Chondrosarcoma (CS) can be categorized based on localization (periosteal, central, and peripheral) or histology, with conventional CS being the most common subtype. However, rarer histological types, such as clear-cell CS, DDCS, and mesenchymal CS, also exist. We present a unique case of DDCS in a 28-year-old male who presented with swelling on the proximal phalanx of the fourth finger. Radiographs showed sclerotic margins and a central diaphyseal lytic lesion. Immunohistochemical analysis using S-100 and Ki67 markers confirmed the diagnosis of DDCS. Treatment involved a multidisciplinary approach, including surgical resection, adjuvant chemotherapy, and radiation therapy. This case underscores the importance of early identification of DDCS and the need for tailored management strategies to address its specific characteristics.