COMPARISON OF INTRAOPERATIVE CYTOLOGY WITH FROZEN-SECTIONS IN THE DIAGNOSIS OF THYROID LESIONS

We retrospectively studied the usefulness of intraoperative cytology ( IOC) and frozen section (FS) in the rapid diagnosis of 68 thyroid lesi ons. In 14 cases of papillary thyroid carcinoma, IOC correctly diagnos ed 13 cases, while FS correctly diagnosed 11 cases. There was no signi ficant difference in sensitivities, and both methods had similar speci ficities. In 21 cass of colloid nodule, IOC was slightly more sensitiv e than FS; IOC correctly diagnosed 16 cases, while FS correctly diagno sed 15 cases. However, the specificity of IOCc was only 71%, but was 9 8% for FS. Of 17 follicular adenomas, FS diagnosed 16 as follicular ne oplasms and misdiagnosed only 1 as a colloid nodule. By contrast, IOC misdiagnosed 9 follicular adenomas as colloid nodules, most of which w ere macrofollicular variants with abundant colloid. Of 11 follicular c arcinomas, FS diagnosed all as follicular neoplasms, while IOC misdiag nosed 3 as colloid nodules. While IOC is not as accurate as FS in the diagnosis of colloid nodules and follicular neoplasms, it is highly se nsitive and specific in the diagnoses of papillary carcinoma and perfo rmance of the technique is rapid and easy. In an intraoperative settin g, IOC is a useful adjunct to FS in screening thyroid nodules for the presence of papillary carcinoma.