[The significance of acid phosphatase activity in the cytologic diagnosis of thyroid malignancy (author's transl)].

The activity of acid phosphatase in thyroid cells obtained by aspiration biopsy with thin needle was studied. The results were compared with those, found by a biochemical method in the operation material of the same cases. It has been proved that there is a significant difference between malignant tumours with cytochemically mostly positive acid phosphatase reaction and colloid adenomas with mostly negative reaction. The results obtained by biochemical method showed significant quantitative differences between malignant and benign tumours. The pattern of acid phosphatase subunits (isoenzymes) in the sera of patients with thyroid malignancies were pathologic and similar to those found in mammary cancers. It can be supposed that the behavior of acid phosphatase in thyreocytes depends on same metabolic properties, perhaps on some process characteristic for malignancy, e.g. growth activity. Even this finding of cytochemically positive acid phosphatase reaction cannot be awaited to be quite specific, it has proved as a useful marker signalizing the possibility of malignancy.