EXPRESSION OF DIPEPTIDYL AMINOPEPTIDASE-IV ACTIVITY IN THYROID-TUMORS- A POSSIBLE MARKER OF THYROID MALIGNANCY

The role of dipeptidyl aminopeptidase TV (DAP IV) activity staining in the investigation of a thyroid mass was explored. The study consisted of two parts: the first part involved DAP TV staining performed on va rious thyroid lesions sampled from operative specimens. These included frozen tissues or cytologic smears. The second part of the study, whi ch is ongoing, prospectively examines the DAP IV activity in fine-need le aspiration (FNA) specimens from patients with a thyroid mass. Resul ts from part 1 of the study indicated that DAP TV activity staining wa s a useful adjunct in distinguishing differentiated carcinoma from ben ign lesions, particularly the ''follicular lesions.'' Preliminary find ings of the second part of the study suggest that DAP IV staining can be applied to FNA specimens. The measure of DAP IV activity and its in fluence on the diagnostic accuracy of FNA remain to be seen.