Case report 368: Enchondroma of the tibia with extensive myxoid degeneration; recurrence with secondary and malignant transformation to highly differentiated chrondrosarcoma

In summary, a case is presented of a 17-year-old young man with a well-defined osteolytic, subchondral lesion in the epi-metaphysis of the proximal end of the tibia. The biopsy material obtained on the first curretage displaced the histological picture of an enchondroma with extensive myxoid transformation, but without clear-cut signs of malignancy. After two years the tumor recurred; now unequivocal signs of malignant transformation were observed radiologically and histologically. A review of the literature indicated solitary enchondroma in this location to be extremely rare and secondary malignant transformation even less common. (orig.)