Cercariform cells for helping distinguish transitional cell carcinoma from non-small cell lung carcinoma in fine needle aspirates.

OBJECTIVE

To determine if cercariform cells, a recently described finding in transitional cell carcinomas (TCC), can aid in distinguishing fine needle aspirates (FNA) of TCC from non-small cell lung carcinoma (NSCLC).

STUDY DESIGN

We compared the incidence of cercariform cells in FNAs of 14 cases of TCC with 22 cases of NSCLC.

RESULTS

Cercariform cells were identified in 8/14 (57%) cases of TCC as compared with 3/22 (14%) cases of NSCLC. Cercariform cells were often present and abundant (> 10 per case) in cases of TCC without squamous differentiation (8/9) but were not present in TCCs with extensive squamous differentiation (0/5). In NSCLCs, cercariform cells were rare (< 10 per case), and the cytoplasmic borders were sometimes not as well defined. The number of cercariform cells was significantly higher in FNAs of TCC without squamous differentiation than in FNAs of NSCLCs (P < .001).

CONCLUSION

The presence of numerous cercariform cells in an FNA favors TCC over NSCLC.