[Immunodetection of thyroid peroxidase in the diagnosis of follicular variants of thyroid papillary cancer].
OBJECTIVE
The aim of this retrospective study was to assess the role of thyroid peroxidase immunodetection in the cytological diagnosis of follicular variants of thyroid papillary cancer (FVTPC) which are difficult to identify by standard cytology.


METHODS
Between 1991 and 1998, 3,505 thyroid fine needle aspiration biopsies were performed by thyroid peroxidase immunocytochemistry and 1,576 patients were operated on. Out of a total of 227 thyroid papillary cancers (TPC), 42 (18.5%) were diagnosed as FVTPC. The results of standard cytology and thyroid peroxidase immunodetection were compared with the histological findings.


RESULTS
The rate of false negatives for TPC in standard cytology was 11% (25/227 cases), with 40% of these false negatives being FVTPC; ten out of 42 (23.8%) cases of FVTPC were not identified by standard cytology. However, cytology with thyroid peroxidase immunodetection diagnosed 224 out of the 227 TPC (99%), and all the FVTPC were correctly identified (100%).


CONCLUSIONS
FVTCP are the most frequent source of false negatives in standard cytology. Thyroid peroxidase immunodetection allows most of these errors to be avoided, and correctly identifies 99% of TPC including FVTPC.
Raffaelli
M
M
Service de chirurgie générale et endocrinienne, hôpital d'adultes de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France.
De Micco
C
C
Lubrano
D
D
Henry
J F
JF
D001707:Biopsy, Needle; D018265:Carcinoma, Papillary, Follicular / Q000175:diagnosis* / Q000601:surgery; D003937:Diagnosis, Differential; D006801:Humans; D007124:Immunoenzyme Techniques; D010544:Peroxidases / Q000032:analysis*; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000201:enzymology*; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000601:surgery
D010544:Peroxidases