Atypical epithelial cells, cannot exclude papillary carcinoma, in fine needle aspiration of the thyroid.
OBJECTIVE
Atypical epithelial cells, cannot exclude papillary thyroid carcinoma (AEC-PTC), in fine needle aspiration (FNA) of the thyroid is a controversial diagnostic category that might cause a dilemma in patient management.


METHODS
Eighty-eight thyroid FNA specimens from 86 patients with a diagnosis of AEC-PTC were retrieved from our files in a 10-year period from December 1996 to December 2006. Of the 86 patients, 57 had follow-up histologic diagnoses and were included in this study. The cytologic and histologic materials were reviewed and correlated.


RESULTS
Of the 57 patients, all had cytologic atypical features suggestive of PTC. Twenty-five cases of PTC were identified at surgery (44%). Review of the cytologic materials identified the following cytologic features, either alone or in combination strongly associated with PTC at resection: rare intranuclear cytoplasmic invagination (INCI), squamoid cytoplasm and psammoma bodies.


CONCLUSIONS
The most common reasons for rendering the diagnosis of AEC-PTC in FNA of thyroid include rare atypical cells in a cystic thyroid nodule or a background of Hashimoto's thyroiditis. The cytologic features of LNCI, squamoid cytoplasm and psammoma bodies should alert the pathologist. Focal cytologic features of PTC in FNA samples are strongly associated with papillary carcinoma on resection.
Department of Anatomic Pathology, The Cleveland Clinic, Cleveland, Ohio 44195, USA.
Dana
D
Weber
Jennifer
J
Brainard
Longwen
L
Chen
D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D015331:Cohort Studies; D004847:Epithelial Cells / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005629:Frozen Sections; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery