2018 Volume 57 Issue 3 Pages 151-158
Objective : We examined the cytological features of medullary carcinoma (MC) of the thyroid gland, including the nuclear dimensions, in order to identify useful diagnostic features for MC that are unlikely to be beset by errors arising from inter-examiner differences, and propose a diagnostic algorithm for improvement of the diagnosis rate.
Study Design : Using cytological specimens obtained from 78 cases of MC, 20 cases of papillary carcinoma, 20 cases of follicular carcinoma and 20 cases of poorly differentiated carcinoma of the thyroid gland, we compared the rates of detection of salt and pepper chromatin, nuclear grooves, nuclear cytoplasmic inclusion bodies and multinucleated carcinoma cells, the amyloid and nuclear areas, the nuclear aspect ratio (ratio of the major axis diameter to minor axis diameter?), and the long diameter of the nuclei in order to identify features useful for the diagnosis of MC.
Results : Diagnosis of MC was confirmed in 59 cases. It was estimated by logistic regression analysis in a further 7 cases. Based on our findings, we suggest the following as useful features for the diagnosis of MC : 1) salt and pepper appearance of the nuclear chromatin ; 2) 4 or more multinucleated carcinoma cells ; 3) presence of amyloid ; 4) nuclear aspect ratio≥1.6 ; 5) CV of the nuclear aspect ratio≥25%, 6) ratio between the minimum and maximum longest diameters of the nuclei≥3.7.
Conclusion : Among the 78 specimens of MC, the diagnosis could be made by cytologic examination in 66 cases (84.6%).
