Is the size of the pancreas useful in diagnosing chronic pancreatitis? An ultrasound based, retrospective study

Background/objectives: According to the widely accepted "Cambridge Classification", one of the morphological criteria for chronic pancreatitis (CP) is enlargement of the pancreas. Increased size seems to be an obvious feature of an inflammatory disease. However, it has never been validated so far, if CP is indeed accompanied by significant enlargement of the pancreas.

Methods: In this retrospective study, reference values for the size of the pancreas (head, body and tail measured in the transverse plane by transabdominal ultrasound) were established from 921 patients without pancreatic disease. Measurements were performed by a single investigator. Subsequently, the size of the pancreas from 72 patients with CP was compared to age- and sex-matched controls.

Results: Calculating the 5th and 95th percentile, reference values of the pancreatic size were as follows: head 1.5-3.1 cm (mean: 2.2); body 0.6-1.6 cm (mean: 1.1); tail 1.4-3.0 cm (mean: 2.1). The size of the pancreas correlated significantly with body height, weight and body mass index. Patients with CP had only a slightly but statistically significantly larger pancreas than controls. Mean values from the CP group were still between the 5th and 95th percentile of matched controls.

Conclusions: Although the pancreas from patients with CP was statistically significantly larger compared to controls, the difference was only marginally. According to these data, it is at least questionable if pancreatic size is a helpful parameter for sonographic evaluation to discriminate chronic pancreatitis from healthy pancreas.