CLEAR NUCLEI OF PAPILLARY THYROID-CARCINOMA CONSPICUOUS IN FINE-NEEDLE ASPIRATION AND INTRAOPERATIVE SMEARS PROCESSED BY ULTRAFAST PAPANICOLAOU STAIN

The Orphan Annie-eyed clear nucleus, defined as a large, optically cle ar nucleus, devoid of chromatin strands, with sharp chromatin rim, is a more specific feature than are nuclear grooves or intranuclear cytop lasmic inclusions in papillary thyroid carcinoma, In addition, this ch aracteristic nuclear feature is detectable at low magnification. Altho ugh these clear nuclei are routinely seen in paraffin sections, they a re inconspicuously seen in conventionally processed touch-imprints and fine-needle aspiration (FNA) smears, Among our two institutions, ther e have been 148 thyroid cases processed by Ultrafast Papanicolaou stai n (UFP), including 43 papillary carcinomas, 38 cellular follicular les ions, and 67 cases of nodular hyperplasia. We observed clear nuclei in all of the cases of UFP-processed FNA and intraoperative smears of pa pillary carcinoma but not of other thyroid lesions. The clear nuclei a re most evident in tumor cells with direct contact to the glass slide and are not seen in tumor cells soaked in cystic fluid, UFP is a valua ble way to detect Orphan Annie-eyed clear nuclei of papillary thyroid carcinoma early in the diagnostic evaluation, either at immediate on-s ite evaluation of FNA or at intraoperative consultation and before the availability of permanent sections.