Fine-Needle Cytology of Hurthle Cell Tumors and Morphometry

摘要

We read with great interest Dr. Auger's article, in which the author exhaustively summarized the data available in the literature concerning the cytology of Hurthle cell lesions, starting from the names of Hurthle cells up to the diagnostic criteria for "true" follicular neoplasm Hurthle cell type. With reference to the discrimination between malignant follicular carcinomas Hurthle cell type (FCHCTs) and benign lesions (nonneoplastic and neo-plastic Hurthle cell lesions), some criteria have been reported, namely syncytial tumor fragments, intranuclear inclusions, prominent nucleoli, and high a nuclear-cytoplasmic ratio as proposed by Kini or scanty colloid, small cell dysplasia, and large cell dysplasia as proposed by Renshaw. Applying his proposed criteria, Renshaw correctly diagnosed 10 FCHCTs, whereas a high number of Hurthle cell adenomas and nonneoplastic lesions fulfilled the same criteria and could not be diagnosed as benign. Auger commented on these data, wishing for an optimal combination of the criteria proposed by Kini and Renshaw with other clinical parameters, whereas the optimal formula remains elusive to date. Some years ago, we performed a morphometric and DNA ploidy study on a series of cytological samples of 40 histologi-cally proven Hurthle cell lesions, namely 20 benign (10 goiters and 10 thyroiditis), 10 tumoral benign, and 10 malignant FCHCT lesions. With regard to the FCHCTs, we observed that the corresponding mean nuclear area (measured in mu~2 ) was the smallest, with the lowest standard deviation (78.14 ± 14.72) compared with the goiters (86.86 ± 20.81), thyroiditis lesions (95.29 ± 24.63) and the adenoma lesions (93.08 ± 26.86). These differences were statistically significant between carcinoma and adenoma lesions, whereas they were not between carcinoma and goiter. In other words, we observed that the nuclei of FCHCTs were smaller and more monomorphous than those of Hurthle cell adenoma, and these data were in agreement with other morphometric and nonmorphometric experiences.