Abstract
Dedifferentiated liposarcoma (DDLPS) with low-grade osteosarcomatous differentiation is extremely rare. However, this subtype is considered at a higher risk of early local recurrence than DDLPS without osteogenic differentiation, underscoring the importance of preoperative radiologic diagnosis. Here, we report a case of DDLPS with low-grade osteosarcomatous differentiation in an 80-year-old male located on the left dorsal thigh, in which long-term imaging follow-up was conducted prior to treatment. Gradual enlargement of calcified components in lipomatous masses may indicate the presence of DDLPS with low-grade osteosarcomatous differentiation.