Unusual Low-Grade Spindle Cell Sarcoma Pattern of Dedifferentiation Occurring in Chondrosarcoma: A Case Report

Chondrosarcoma is a cartilage forming tumour, typically found in flat bones such as the ilium. It is known to have a male preponderance and encountered in the older age group. The lesions are locally aggressive, and onset of symptoms is gradual. Dedifferentiated chondrosarcoma typically has 2 microscopic components, whereby the low-grade cartilaginous lesion is seen with a high grade sarcomatous component with an abrupt transition between the 2 zones [1]. This pattern of dedifferentiation occurs in about 10% of chondrosarcomas [2,3]. The femur is involved in about 30% of these lesions and majority of the tumors are seen beyond the sixth decade [1]. We report an unusual pattern of dedifferentiation occurring in a chondrosarcoma where the pattern of dedifferentiation was that of a low-grade spindle cell sarcoma