"Mass-forming" pancreatitis masquerades as pancreatic carcinoma

When a patient with a hypervascular pancreatic mass has a history of alcoholism and pancreatitis, and normal serum levels of CA 19-9, mass-forming pancreatitis should be kept in mind as a differential diagnosis of pancreatic carcinoma.

Chronic and/or acute pancreatitis sometimes produces a pancreatic mass; and differentiation from pancreatic carcinoma is of clinical importance.

A total of 13 Japanese patients with mass-forming pancreatitis were retrospectively reviewed in order to clarify clinical features which can differentiate between mass-forming pancreatitis and pancreatic carcinoma.

Six of the 13 patients had a history of chronic pancreatitis or acute pancreatitis from 8 mo to 11 yr previously. Eleven patients were alcoholic. Serum carcinoembryonic antigen and carbohydrate antigen 19-9 levels were within normal limit in 9 of 12 patients examined and in all 12 patients examined, respectively. The pancreatic mass was located in the head of the pancreas in 9 patients, in the body in 1 and in the tail in 3. The mean greatest diameter of the mass was 2.8 cm. Six of the 13 pancreatic masses were hypoechoic by ultrasonography. Ten of the 13 pancreatic masses were of low-density by computed tomography. Two of the five masses examined were hypervascular at arterial and/or venous phase by angiography. Significant factors differentiating from pancreatic carcinoma were age, alcoholism, history of pancreatitis, serum levels of CA 19-9 and hypervascularity. Follow-up ultrasonography and/or computed tomography showed diminution of the mass in 1 to 2 mo in four patients, together with decrease of serum carcinoembryonic antigen and/or carbohydrate antigen 19-9 levels in two of the four patients.