Enchondroma versus Chondrosarcoma in Long Bones of Appendicular Skeleton: Clinical and Radiological Criteria—A Follow-Up

As of today two types of cartilage tumors remain a challenge even for the orthopedic oncologist: enchondroma (E), a benign tumor, and chondrosarcoma (LGC), a malignant and low aggressiveness tumor. A prospective study of 133 patients with a cartilaginous tumor of low aggressiveness in the long bones of the appendicular skeleton was done to prove this difficult differential diagnosis. Parameters including medical history and radiological and nuclear imaging were collected and compared to the result of the biopsy. A scale of aggressiveness was applied to each patient according to the number of aggressiveness episodes present. A comparison of the results of the biopsy with the initial diagnosis made by the orthopedic oncologist based solely on clinical data and imaging tests was also made. Finally, a management algorithm for these cases was proposed. A statistical significance for LGC resulted from the parameter as follows: pain on palpation, involvement of cortical in either the CT or MRI, and Tc99 bone scan uptake equal or superior to anterosuperior iliac crest. In our series, a tumor scoring 5 points or higher in the scale of aggressiveness can have 50% more chance of being LGC. When compared with the gold standard (the biopsy), surgeon's initial judgement showed a sensitivity of 73.5% and a specificity of 94.1%.