OBJECTIVETo determine the clinicopathologic characteristics and the relationship between related gene expression and pathobiologic behavior of pancreatic mucinous noncystic adenocarcinoma.

METHODSAmong the 249 pancreatic carcinoma cases from the department files, 6 tumors were identified to meet the pathologic criteria of colloid carcinoma. Envision immunohistochemical staining technique was used to detect expression of p21(ras), p21(WAF1), p16, p33(ING1), p53, ATM, MDM2, PCNA, Cyclins (D1, D3, A, B and E). Intra- and extra- cellular mucin production were determined by AB-PAS staining. Clinically, all of 6 cases were followed to June, 2003.

RESULTSIn all 6 cases, the tumors were located in the head of the pancreas and all displayed similar microscopic findings. Duodenal invasion was seen in 4 cases and perineural invasion was seen in 1 case. Tumor metastasis in the liver was seen in 2 cases and in the regional lymph nodes in 2 cases. Positive immunostaining was seen in 5 cases with p21(ras), 3 cases with p21(WAF1), 1 case with p16, 4 cases with p33(ING1), 2 cases with p53, 3 cases with ATM, 3 cases with MDM2, 6 cases with PCNA, 3 cases with cyclinA, 3 cases with cyclinD1, 4 cases with cyclinD3, 4 cases with cyclinB and 6 cases with cyclinE. Both extracellular and intracellular mucin was strongly positive for AB-PAS staining. Clinical follow-up found that 2 patients died of their tumors at 14 and 20 months. Three patients were alive after 28, 49 and 87 months of follow-up. One case were lost contact.

CONCLUSIONSPancreatic mucinous noncystic adenocarcinoma has distinct morphologic features and biologic behavior. Multiple gene products including many cyclins may be involved in the pathogenesis of pancreatic colloid carcinoma. The tumor has an aggressive behavior with a high frequency of invasion and metastases, though the prognosis could be better than that of ordinary ductal adenocarcinoma of pancreas.