PERITONEAL EXFOLIATIVE CYTOLOGY AND KI-RAS MUTATIONAL ANALYSIS IN PATIENTS WITH PANCREATIC ADENOCARCINOMA

This is the first description of the detection of pancreatic adenocarc inoma peritoneal metastasis by established radiolabeled polymerase cha in reaction (PCR) based Ki-ras mutational analysis. The present study evaluates both routine cytology and Ki-ras mutational analysis in the detection of peritoneal micrometastases in 24 subjects with pancreatic adenocarcinoma compared to seven control cases of chronic pancreatiti s and seven control cases of cholecystitis. Locoregional extension, va scular invasion, and distal metastases were confirmed in 21/24 (88%) o f the subjects with pancreatic adenocarcinoma by computed tomography, angiography, endosonography, or laparoscopy. The most common site of h istologically confirmed extrapancreatic involvement was the vasculatur e (29%), followed by the liver (25%), duodenum (17%), peritoneum (17%) , and lymph nodes (12%). Peritoneal lavage cytology was positive in 3/ 24 (12%) cases of pancreatic carcinoma while Ki-ras codon 12 mutationa l analysis was positive in 2/24 (8%). Two histologically confirmed cas es of peritoneal metastases were not detected by either methodology, w hile peritoneal lavage cytology detected malignant cells in one case w ith histologically confirmed lymph node metastasis.