Defining the origin of adenocarcinoma cell in body fluid cytology: Immunohistochemical staining using the cell transfer method

Objectives : We studied the usefulness of four immunochemical markers in defining adenocarcinoma cell origin in body cavity fluid. Study Design : Immunochemical CK7, CK20, Napsin A and Villin expression was retrospectively studied in cytological specimens from 108 surgically resected adenocarcinoma cases involving the lung, breast, stomach, pancreas, colon, and ovary using cell transfer. Results : CK7 (+) CK20 (+) was expressed in 80% (8/10) of pancreas specimens and CK7 (+) CK20 (−) in all (15/15) of breast specimens. CK7 (+) CK20 (−) was expressed in 95% (20/21) of lung specimens and 95% (18/19) of ovarian specimens. CK7 (+) CK20 (+) and CK7 (+) CK20 (−) were expressed in 80% (24/30) of stomach specimens. CK7 (+)CK20 (−) and CK7 (−)CK20 (+) were expressed in 77% (10/13) of colon specimens. Napsin A was positive in 71% (15/21) of lung specimens, 7% (2/30) of stomach specimens, and 16% (3/19) of ovarian specimens. Villin was positive in 100% (13/13) of colon specimens, 77% (23/30) of stomach specimens, and 16% (3/19) of ovarian specimens. Conclusions : Four immunochemical markers are useful for determining adenocarcinoma cell origin in body cavity fluid.