Two types of mucin-producing cystic tumors of the pancreas: Diagnosis and treatment

Abstract

Background. This study focuses on clinicopathologic, imaging, and prognostic differences between two types of mucin-producing cystic tumors of the pancreas, with the aim of appropriate management of these tumors. Methods. Forty-six patients with mucin-producing cystic tumors underwent operation. The types of tumors were as follows: mucinous cystic neoplasm, adenoma (6) and adenocarcinoma (12); intraductal papillary tumor, adenoma (10) and adenocarcinoma (18). Results. Gender, age, symptoms, signs, tumor location and size, and the presence or absence of communication with the pancreatic duct differed between the two types. Mucinous cystadenocarcinomas showed deep invasion more often than intraductal papillary adenocarcinomas. Lymph node involvement was seen in 58% of mucinous cystadenocarcinomas but in only 22% of intraductal papillary adenocarcinomas. Tumors with mural nodules tended to show deep invasion and nodal metastasis. All four intraductal papillary tumors smaller than 3 cm without mural nodules were adenomas. Imaging studies allowed accurate differentiation between the two types but not between adenomas and adenocarcinomas. Five-year survival rates for patients with adenomas, mucinous cystadenocarcinomas, and intraductal papillary adenocarcinomas were 100%, 33%, and 81%, respectively. Conclusions. Mucinous cystic neoplasm necessitates complete tumor excision with wide dissection of lymph nodes including paraaortic nodes. Intraductal papillary tumor requires only peripancreatic node dissection; for tumors smaller than 3 cm without mural nodules, node dissection may be unnecessary.