Avoiding an overdiagnosis of pancreatic pseudocysts

Thirty-six cases of pancreatic pseudocysts were retrospectively analyzed, to evaluate the clinical features of the pseudocysts which could not be differentiated from the neoplastic cysts until laparotomy.

Thirty-one out of 36 cases were diagnosed correctly to be a pseudocyst, in which 10 cases (32.3%) were treated by surgery. Five out of 36 cases were diagnosed to be neoplastic pancreatic cysts (mucinous cystadenoma or cystadenocarcinoma in 4 cases, serous cystadenoma in 1) in which all cases were treated by surgery (100%). To determine the clinical factors contributing to a correct or false diagnosis of pseudocysts, 14 clinical objects were categorized into several factors and analyzed using a contingency table.

The clinical factors, including a "history of pancreatitis" (P = 0.070), "upper abdominal pain" (P = 0.083), an "age of less than 42 years" (P = 0.070), and an "elevated serum amylase level on admission" (> or = 200 IU/L, P = 0.067) were all thought to be helpful in establishing a correct diagnosis of pancreatic pseudocyst. In the morphological studies of computed tomography and ultrasonography, "multicystic lesions" (P = 0.045) and "nodular or irregular thickening of the cyst wall" (P = 0.006) significantly mislead us into making a diagnosis of a neoplastic cyst.

In conclusion, the morphological features of a multicystic pattern, with either nodular or irregular thickening of the cyst wall, also belong to the common features of the pancreatic pseudocysts. Since these features tended to be diagnosed as neoplastic, other clinical factors should thus be referred to, in a comprehensive manner, to establish a correct diagnosis of pancreatic pseudocyst.