Diagnostic p53 immunostaining of endobiliary brush cytology - Preoperativecytology compared with the surgical specimen

BACKGROUND: Endobiliary brush cytology is important in the distinction of m alignant and benign causes of extrahepatic bile duct obstruction. The addit ional diagnostic value of p53 immunostaining an these cytology specimens wa s assessed. METHODS: All patients with extrahepatic bile duct obstruction who underwent endoscopic retrograde cholangiopancreatography (ERCP) with endobiliary bru sh cytology and subsequent surgery at the Academic Medical Center in Amster dam during a 3-year period were studied. p53 Immunocytology was compared wi th the corresponding conventional light microscopic cytology and p53 immuno staining of the subsequent surgical specimen. RESULTS: Fifty-three patients with the following diagnoses were included: p ancreatic carcinoma (23), bile duct carcinoma (15), ampullary carcinoma (5) , lymph node metastases (2), carcinoma of unknown origin (4), chronic pancr eatitis (3), and primary sclerosing cholangitis (1). Fifty-one percent of t he carcinomas showed positive p53 immunostaining; all four surgical specime ns without carcinoma were negative. The sensitivities of conventional light microscopic cytology, p53 immunocytology, and both tests combined were 29% , 24%, and 43%, respectively. These sensitivities were higher in cases of b ile duct carcinoma (46%, 40%, and 66%) compared with cases of pancreatic ca rcinoma (13%, 9%, and 22%). Specificities of both tests were 100%. CONCLUSIONS: p53 Immunostaining on endobiliary brush cytology may be helpfu l in the diagnosis of malignant extrahepatic bile duct stenosis, especially in patients with bile duct carcinoma. Cancer (Cancer Cytopathol) 1999;87:3 06-11. (C) 1999 American Cancer Society.