Usefulness of Ki-67, PCNA, c-erbB-2 and CK 19 in the diagnosis of some thyroid follicular tumors
Ioana Zosin1, Marioara Cornianu2, Ioana Golu1, Melania Balas1 & Aurora Milos1
This study represents a complex evaluation of a group of 26 cases with thyroid nodular disease (TND), using different diagnostic methods. Clinically and by means of ultrasonography, 12 patients were suspected of malignancy. Fine-needle aspiration biopsy (FNAB) detected mainly suspicious (12 cases) and malignant smears (5 cases). The microscopic examination of surgical specimens established the following diagnosis: follicular adenoma FA (4 cases), papillary hyperplasia PH (2 cases), papillary carcinoma PC (10 cases), follicular carcinoma FC (2 cases) and Hürthle cell tumors HCT (8 cases). PCs were represented by occult, classic forms and variants, HCT included adenomas, carcinomas and some adenomas showed an uncertain malignant behaviour. Metastases were diagnosed in 6 cases.The expression of Ki-67 antigen, proliferating cell nuclear antigen (PCNA), cytokeratin (CK) 19 and c-erbB-2/neu oncogene was evaluated by IHC (DAKO LSAB method) in all surgical specimens. For IHC we used paraffin-embaded sections and monoclonal antibodies (mAb): MIB-1, PC10, mAb against c-erbB-2 and mAb CK 19. The most interesting conclusions regard the expression of CK 19 and c-erbB-2. CK 19 was diffusely and intense expressed in all cases of PCs, 1 case of Hürthle cell carcinoma (HCC), but never in PH. There was no apparent difference in immunostaining reactivity between tumors with or without metastases. Follicular and oxyphilic cell neoplasia showed at best a focal staining. Regarding the expression of c-erbB-2, 50% of PCs presented a cytoplasmic staining pattern and the rest a mixed one (cytoplasmic and membranous). Some FC and HCC showed also a mixed staining. The epithelial malignant tumors with metastases presented more expressed reactivity versus the cases without metastases.
The used corroborated investigations helped us to obtain an accurate diagnosis in some peculiar epithelial thyroid tumors.