Chondromyxoid fibroma is a rare benign cartilaginous tumor containing varying amounts of chondroid, fibromatoid, and myxoid components. The lesion is most frequent in 2nd and 3rd decades of life with male predilection. It usually involves metaphyseal region of long tubular bones. The most common location is proximal tibial metaphysis. On plain films, the lesion is expansile, eccentric, sharply circumscribed, lobulated, and radiolucent and is usually parallel to the long axis of the bone. There is bone destruction in the involved segment with a sclerotic margin but no periosteal reaction. There may be septations (very well seen in this case) as well as matrix calcification in some cases. Case produced with permission, courtesy of Dr. Frank Gaillard. Radiopaedia. Complete case is here.