[Tumor markers in the cytodiagnosis of thyroid nodules. Detection of dipeptidyl aminopeptidase IV (DAP IV) activity].
Dipeptidyl-aminopeptidase IV (DAP IV), an exopeptidase involved in T-cell activation is absent from normal thyroid tissue but highly expressed by malignant thyroid cells. It has been suggested to be a useful adjunct for the diagnosis of malignant thyroid tumors on fine needle aspirates (FNA). To assess this assumption DAP IV activity was demonstrated by histochemical staining on FNA performed on 102 thyroid nodules at the time of surgery (60 macrofollicular adenomas, 15 microfollicular adenomas. 7 Hashimoto's thyroïditis, 3 Graves' disease. 13 papillary carcinomas and 4 follicular carcinomas). A staining score based on the percentage of positive epithelial cells and staining intensity was established for each case and results were compared to histological diagnosis. Most cells in malignant tumors were deeply stained except in one case of papillary carcinoma. Null or very low scores resulting from light or medium staining of less than 40% of the cells were obtained in 78/85 benign nodules. In 6 macrofollicular adenomas and in 1 case of thyroiditis staining score was as as high as in carcinomas. DAP IV staining was correlated to malignancy in all follicular tumours (4 malignant tumours were positive and 15 benign were negative). The sensitivity for diagnosis of malignancy was 94.1% and the specificity 91.7%. This study brings confirmation that DAP IV activity detection could be an useful adjunct to cytological examination for the distinction between benign and malignant thyroid nodules, especially in cases of follicular tumors.
Zoro
P
P
Laboratoire d'Anatomie Pathologique, CHU Nord, Marseille.
Vassko
V
V
Garcia
S
S
Pazart
L
L
Aho
S
S
De Micco
C
C
D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D003581:Cytodiagnosis / Q000379:methods*; D018819:Dipeptidyl Peptidase 4 / Q000032:analysis*; D005069:Evaluation Studies as Topic; D006801:Humans; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000201:enzymology / Q000473:pathology*
D014408:Biomarkers, Tumor; D018819:Dipeptidyl Peptidase 4