Abstract: Pancreatic cystic neoplasms are very rare lesions that represent approximately 12% of all pancreatic cysts,Cystoadenocarcinoma is about 1% of all pancreatic carcinolna. From 1989 to 1993 we observed 7 patients with pancreatic cystic carcinoma;4 cystoadenocarciooma and 2 mucinousadenocarcinoma,1 adenocarci-noma. Two patients was mistaken for pseudocysts,one patietits for cyst of the spleen. Mucinouscystoadenoma is potential malignancy tumour,2 patients with cystoadenoma were mistaken by internal drainage and led to recurrence and metastasis.It is important problem to differentiate from pancreatic pseudocyst at preoperation.