Importance of foamy macrophages only in fine needle aspirates to cytologic diagnostic accuracy of cystic metastatic papillary thyroid carcinoma.
OBJECTIVE
To investigate the important cytologic features and thyroglobulin (Tg) level in fine needle aspiration cytology (FNAC) of cystic metastasis of papillary thyroid carcinoma (PTC) and to find some independent cytologic factors that enhance the diagnostic accuracy of cystic lymph node metastasis without identifiable tumor cells or high levels of Tg.


METHODS
Two hundred forty-four aspiration cytology cases with correspondent tissue specimens were included in the study. Cytologic features and FNAC Tg level were evaluated in each case.


RESULTS
Twelve cases showed cystic lymph node metastasis in tissue slides but negative cytology with a mean FNAC Tg level of 413.3 ng/mL (range, 71.9-963.0). Out of these, 10 cases (83.3%) demonstrated only foamy macrophages.


CONCLUSIONS
Foamy macrophages only without Tg level information in FNAC could raise the possibility of cystic metastatic PTC even if no identifiable tumor cells are found.
Department of Pathology, Yonsei University Health System, Yonsei University College of Medicine, Seoul, South Korea.
Ja Seung
JS
Koo
Jin Young
JY
Kwak
Woohee
W
Jung
SoonWon
S
Hong
D000231:Adenocarcinoma, Papillary / Q000378:metabolism / Q000556:secondary* / Q000601:surgery; D044963:Biopsy, Fine-Needle; D005260:Female; D005487:Foam Cells / Q000473:pathology*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013954:Thyroglobulin / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
D013954:Thyroglobulin