KLK3 and adenocarcinoma: Ascitic fluid cytology studies confirmed the presence of malignant cells. Immunohistochemistry staining positive for prostate-specific antigen (PSA) and Ber-EP4 (a monoclonal antibody used to distinguish between adenocarcinoma and reactive mesothelium) was compatible with primary prostate adenocarcinoma (Figures 2-3) [2].