Elevation of serum alkaline phosphatase in clear cell chondrosarcoma of bone.

BACKGROUND

Clear cell chondrosarcoma is a rare bone tumor, which is sometimes misdiagnosed as a different bone neoplasm.

METHODS

The files of 6 patients with clear cell chondrosarcomas were reviewed. Histological slides, radiographic studies, and pre- and post-operative serum alkaline phosphatase (ALP) levels were evaluated. Molecular and histochemical analyses of ALP were documented in one case of clear cell chondrosarcoma.

RESULTS

Pre-operative serum ALP levels were elevated in 3 patients, and were normal in another 3 patients. After removal of the tumors, the enzyme levels decreased in all patients and returned to normal in 3 patients, who had pre-operative high ALP levels. Enzyme histochemical and molecular analyses demonstrated that the tumor produced ALP.

CONCLUSIONS

Clear cell chondrosarcoma produces ALP, which can be used as a tumor marker in diagnosis and follow-up.