Pseudocyst formation in hereditary pancreatitis.

The previously estimated incidence of pseudocyst formation in hereditary pancreatitis is approximately 10%. Our experience in nine patients with hereditary pancreatitis yielded five surgically documented pseudocysts and three additional patients with radiographically documented mass effects. Recent studies have shown a 20% spontaneous regression rate for pancreatic pseudocysts (of all etiologies), when evaluated by B-mode ultrasonography; our experience suggests that the incidence of pseudocyst formation in hereditary pancreatitis is considerably higher than previously suspected. Ultrasonography is thought to be an excellent method for diagnosing this entity, of evaluating mass effects identified on radiographic studies, and of providing sequential evaluation of pseudocysts treated surgically or conservatively.