Ki-67 and AgNOR proliferative markers as diagnostic adjuncts to fine needle aspiration cytology of thyroid follicular lesions.
OBJECTIVE
To differentiate hyperplastic nodules (HPN), follicular adenoma (FA) and follicular carcinoma (FCA) of the thyroid by cytomorphologic features combined with argyrophilic nucleolar organizer regions (AgNORs) and Ki-67 proliferative markers on fine needle aspiration cytology.


METHODS
Cytomorphologic patterns, along with two proliferation markers, Ki-67 and AgNORs, in fine needle aspirates of 123 histologically confirmed cases of thyroid follicular lesions, including 39 hyperplastic nodules, 70 follicular adenomas and 14 cases of follicular carcinomas, were recorded.


RESULTS
Mean AgNOR (mAgNOR) counts and Ki-67 labelling index (LI) were consistently higher in FCA in comparison to FA and HPN irrespective of the cytologic patterns in fine needle aspiration smears. Between benign and malignant lesions, an overlap of 1.83% at the cutoff point of 4.0 was observed in cases of mAgNORs, whereas it was 11.09% at a cutoff of 5.0 in cases of Ki-67 LI.


CONCLUSIONS
mAgNOR counting in fine needle aspiration smears is more sensitive, simple and cost effective as compared to Ki-67 LI for differentiating between benign and malignant thyroid follicular neoplasms.
Mehrotra
Anju
A
Department of Pathology, King George's Medical College, Lucknow, UP, India.
Goel
Madhu Mati
MM
Singh
Kamlesh
K
D018263:Adenocarcinoma, Follicular / Q000737:chemistry* / Q000473:pathology*; D000236:Adenoma / Q000737:chemistry / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis*; D009697:Nucleolus Organizer Region / Q000473:pathology; D016622:Silver Staining; D013964:Thyroid Neoplasms / Q000737:chemistry* / Q000473:pathology*; D016606:Thyroid Nodule / Q000737:chemistry / Q000473:pathology
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen