Intraductal papillary mucinous tumors (IPMT)

MUC1 and MUC2 in pancreatic neoplasia

MUCs are glycoproteins with various roles in homeostasis and carcinogenesis. Among other actions, MUC1 may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, participating in cancer progression. In contrast, MUC2 is normally found only in goblet cells, where it contributes to the protective barrier function of these cells. Recently, a tumour suppressor role has been demonstrated for MUC2, and both MUC1 and MUC2 appear to have important roles in pancreatic neoplasia. MUC1 appears to be a marker of aggressive phenotype and may facilitate the vascular spread of carcinoma cells. In contrast, MUC2 is rarely detectable in aggressive pancreatic tumours, but is commonly expressed in intraductal papillary mucinous neoplasms (IPMNs), which are rare, indolent tumours, in intestinal IPMNs, and in indolent colloid carcinomas. MUC2 appears to be not only a marker of this indolent pathway, but also partly responsible for its less aggressive nature. Thus, in pancreatic neoplasia, MUC1 and MUC2 have potential diagnostic and prognostic value as markers of aggressive and indolent phenotypes, respectively, and have potential as therapeutic targets.

Surgical treatment of incidentally identified pancreatic masses

INTRODUCTION

With the improved quality and widespread availability of diagnostic abdominal imaging, incidental intra-abdominal lesions (incidentalomas) are being increasingly identified. Our objective was to characterize the clinical features of asymptomatic patients with incidentally discovered pancreatic lesions and to assess the accuracy of preoperative radiologic diagnosis against the final histologic diagnosis.

METHODS

This cohort study is based on prospectively collected data from a surgical pancreatic database. Preoperative imaging of patients with pancreatic incidentalomas was retrospectively and independently assessed by 2 radiologists blinded to the final histologic diagnosis. Seven patients who were asymptomatic and had incidentally discovered pancreatic masses underwent complete resection of the mass. The clinical features and patient survival data were analyzed. The accuracy of preoperative imaging was assessed by comparing the preoperative diagnosis to the final histologic diagnosis.

RESULTS

Lesions most commonly occurred in females (6 patients) and in the tail or body of the pancreas (5 patients). The histologic type of the masses included neuroendocrine tumour (3), serous cystadenoma (2), intraductal papillary mucinous tumour (1) and papillary cystic and solid tumour (1). Preoperative imaging was unreliable in predicting the histologic type of the resected mass.

CONCLUSIONS

Our findings suggest that preoperative imaging does not always predict the surgical histologic type of pancreatic incidentalomas. Unless the diagnosis of serous cystadenoma is certain, surgical resection should be considered in low-risk patients in whom pancreatic masses are found incidentally.