"Cellular swirls" and similar structures on fine needle aspiration cytology as diagnostic clues to papillary thyroid carcinoma: a report of 4 cases.

BACKGROUND

"Cellular swirls" are one of the recently recognized criteria for diagnosing papillary thyroid carcinoma (PTC). Following its initial description, no publications have appeared in the literature.

CASE

Thyroid aspirates from 4 adult patients, 3 with a clinical diagnosis of PTC and 1 diagnosed as nodular goiter were studied. Cytologically, all 4 cases showed classic features of PTC. In addition to the characteristic cytomorphology of PTC, all 4 cases showed cellular swirls, which are a newly recognized diagnostic criterion of PTC. Also seen were structures that partially resembled cellular swirls. These latter structures were found to be more prominent in the aspiration smears than the characteristic swirls and, therefore, we strongly think that even the partical swirls with contiguous cellular sheets exhibiting similar nuclear morphology are also useful in prompting a search for "complete swirls" that are thought to be specific for PTC.

CONCLUSION

Cellular swirls and similar structures seen on fine needle aspiration cytologic smears can serve as useful features in the diagnosis of PTC.