[Demonstration of osteoclastic acid phosphatase in the serum of patients with giant cell tumors. Preliminary study].

Starting from the fact that an ultrastructural cytochemical study of the Giant-Cell Tumour demonstrated the presence of a large amount of lysosomic acid phosphatase in the tumour cells, an attempt was made to evidence the presence of this enzyme in the serum of patients bearing such a type of bone tumor. Acrylamide gel electrophoresis of the serum allowed one to separate a number of isoenzyme with acid phosphatase activity and to characterize at least two bands different from those secreted by prostate, blood platelets, liver or spleen. The comparison between zymograms of normal and pathological sera, more particularly in Paget disease, led to consider that these two bands had an osteoclastic origin. Besides, these bands vanish after tumor eradication. Acrylamide gel electrophoresis of serum provides therefore a means to support the preoperative diagnosis of Giant-Cell Tumor and, eventually, to detect an early recurrence of the disease.