An Immunostaining Panel for Diagnosis of Malignancy in Mucinous Tumors of the Pancreas

Background.--The diagnosis of malignancy in pancreatic mucinous cystic tumors depends on demonstrating invasion that may be focal and require extensive sectioning. Objective.--To explore markers that may indicate malignant potential in mucinous cystic tumors. Design.--Routinely processed sections from resected specimens of 12 normal pancreata, 14 pancreata with chronic pancreatitis, 9 mucinous cystic tumors, and 30 invasive adenocarcinomas were immunostained with antibodies to p53, HER.2/neu, epithelial growth factor receptor (EGFR), transforming growth factor [Alpha] (TGF-[Alpha], and Ki-67. Results.--Expression of p53, HER.2/neu, and Ki-67 was significantly more frequent in mucinous tumors than in normal pancreatic tissue and chronic pancreatitis tissue (P = .0003 to .05). Strong expression (more than one third of cells positive) and strong intensity (2+ and 3+) of staining of p53 and EGFR were seen only in carcinomas. Coexpression of p53/HER-2/neu and EGFR/HER.2/neu and a frequency of Ki-67+ nuclei of greater than 5% of cells discriminated between mucinous tumors and normal pancreatic tissue and chronic pancreatitis tissue, p53 expression was significantly more frequent in carcinomas than in mucinous tumor (P = .0326). Coexpression of p53/EGFR discriminated between mucinous tumors and carcinomas; however, TGF-[Alpha] was not discriminative. Conclusions.--The immunostaining panel of p53, HER2/neu, Ki-67, and EGFR can be helpful in indicating malignant potential in mucinous tumors of pancreas in routine pathology practice. (Arch Pathol Lab Med. 2001;125:765-769)
The detection of malignant potential in pancreatic neoplasms, especially in mucinous cystic tumors (MTs), is of clinical importance, since the surgical therapy is different for benign and malignant neoplasms. Currently, [...]