Dark and pale cerebriform nuclei in FNA smears of usual papillary thyroid carcinoma and its variants.

Abstract

The dark (hyperchromatic) cerebriform nucleus was recently described as a frequent finding in histopathology sections of papillary carcinoma of the thyroid. In the present study, we tried to determine the frequency of dark cerebriform nuclei in the fine-needle aspiration (FNA) smears of papillary thyroid carcinomas and compared it with those of other thyroid lesions, such as follicular neoplasms and benign hyperplastic lesions. In addition to the above-mentioned nuclear feature, pale (hypochromatic) cerebriform nucleus and other well-established cytomorphological criteria used in the diagnosis of papillary thyroid carcinomas were analyzed. FNA smears of a total of 102 cases comprising of 61 papillary carcinomas, 10 cases of suspicious papillary carcinomas, 12 follicular neoplasms, and 19 benign hyperplastic lesions were studied. Both the dark and pale cerebriform nuclei were found in a significantly higher number of cases of papillary thyroid carcinomas compared with follicular neoplasms (P = 0.0003 and P < 0.0001, respectively) or benign hyperplastic lesions (P = 0.0004 and P < 0.0001, respectively). Review sections available in 24 cases showed agreement between the cytopathological and the histopathological diagnoses in 18 (94.7%) of 19 papillary carcinomas. Thus, the dark and pale cerebriform nuclei can be regarded as useful cytomorphological parameters in the diagnosis of papillary thyroid carcinoma.