Fine-needle aspiration features of paraduodenal pancreatitis (groove pancreatitis): a report of three cases.

Chronic pancreatitis is notorious for mimicking both the clinical and radiologic presentation of pancreatic carcinoma. Paraduodenal pancreatitis is believed to result from focal chronic pancreatitis which affects the minor papilla of the duodenum. Currently, there is limited information available regarding the cytologic features of paraduodenal pancreatitis. In this study, we report the cytologic features of three patients with paraduodenal pancreatitis who had EUS-guided FNAs of the pancreas. The cytologic features were highly variable between cases, likely due to sampling of the various components of paraduodenal pancreatitis. The most common findings were spindled stromal cells, foamy cells, and granular debris. Although most often interpreted as negative for malignancy, the sampling of an area with abundant spindle cells or Brunner gland hyperplasia can mimic neoplasia. Careful attention to the clinical history and radiologic description can help to prevent over-diagnosis on FNA.