Revisiting cercariform cells: Small cell carcinoma masquerading as cercariform cells.

Cercariform cells are slender cells with a bulbous end and a unipolar long cytoplasmic process, resembling Schistosoma cercariae. Since their first description in urothelial carcinoma, multiple studies have attempted to explore their utility in distinguishing metastatic urothelial carcinoma from other common malignant neoplasms, such as adenocarcinoma and squamous-cell carcinoma. Although not pathognomonic, they are most commonly encountered in urothelial carcinoma, but they can also be seen in other neoplasms, raising the possibility that this cytomorphological feature can be exploited to aid in diagnosis.