Hai nghiên cứu gần đây dường như đã giải quyết vấn đề đầu tiên. Vào ngày thứ hai, một giả thuyết đã được nâng cao. Hơn 90% của MCNs xảy ra trong cơ thể và đuôi của tuyến tụy, nơi chúng hình thành các khối u nang tròn lớn (hình 57,2) | PART IV Table Clinicopathologic features of mucinous cystic neoplasms. Ratio of women to men 9 1 Age range 23-78 mean 47 years Localization 90 in the body-tail region Morphology mucinous cyst without duct communication Prognosis excellent after complete resection Figure Mucinous cystic adenoma in a 42-year-old woman the multicystic tumor is well demarcated. the seminal paper by Compagno and Oertel in 1978 there has been a debate about the prognosis and origin of these neoplasms. Two recent studies seem to have settled the first issue. On the second a hypothesis has been advanced. More than 90 of MCNs occur in the body and tail of the pancreas where they form large round cystic tumors Fig. showing a unilocular or multilocular cut surface and diameters between and 23 cm. Mul-tilocularity localization in the head region and presence of papillary projections and stromal nodules all correlate with an associated invasive component. The cystic spaces are lined by mucin-producing epithelial cells that are supported by an ovarian-like stroma which may be focally hyalinized. MCNs composed of cells exhibiting only minimal atypia are adenomas whereas those with moderate or even severe atypia are borderline tumors and carcinomas respectively. Invasive MCNs show the pattern of either a DAC or an undifferentiated carcinoma with osteoclast-like giant cells. The stroma may also contain sarcomatous nodules. MCNs comprise approximately 1 in our series of pancreatic exocrine tumors and among the cystic neoplasms they account for approximately . The higher frequencies that have been reported in some previous studies are probably due to the fact that IPMNs and MCNs were not clearly distinguished from each other or were still interpreted as a single entity. The clear differentiation of MCNs from IPMNs also revealed that MCNs are extremely rare in men. The age at diagnosis ranges from 23 to 78 years though patients with invasive carcinoma are often older than 50 .
