Differentiation between Papillary Carcinoma and Adenomatous Nodule using Three-dimensional Nuclear Analysis is Useful for Morphologically Indeterminate Cases of Thyroid Tumor

Six nuclear parameters (number of focus layers, pixel count, three-dimensional luminance coefficient variation (3D-CV), roundness, intranuclear inclusion, and nuclear groove) were measured to examine the usefulness of discriminant analysis between papillary carcinoma of the thyroid (Papillary ca) or adenomatous nodule/goiter (A. nodule) using Mahalanobis distance.   Forty-two of 442 indeterminate specimens were histologically diagnosed with Papillary ca or A. nodule. Six nuclear parameters for each specimen were examined to conduct discriminant analysis between papillary ca and A. nodule using Mahalanobis distance.   The number of nuclear focus layers, pixel count, and intranuclear inclusion [×10-1] of Papillary ca were higher than those of A. nodule (3.91 ± 0.44, 888 ± 257, and 2.2 ± 4.2 vs. 3.59 ± 0.54, 785 ± 111, and 1.3 ± 3.5). The 3DCV [×10-3], roundness [×10-1], and nuclear groove [×10-1] of Papillary ca were lower than those of A. nodule (12.1 ± 5.7, 8.464 ± 0.144, and 2.2 ± 4.2 vs. 15.1 ± 5.2, 8.602 ± 0.078, and 3.3 ± 4.9). Positive discrimination rates of each specimen were 96.3% and 73.3% for Papillary ca and A. nodule, respectively.   The discriminant analysis for each specimen is reasonable and useful for providing high discrimination rates.