Multicystic adenomatoid hamartoma of the pancreas: a hitherto undescribed pancreatic tumor occurring in a 3-year-old boy.

This report describes an unusual pancreatic tumor in a 3-year-old boy. He presented with abdominal pain secondary to pancreatitis and was found to have a complex, multicystic lesion within the head of the pancreas. He subsequently underwent a pancreatoduodenectomy. Grossly, the mass was 3 cm, multicystic, and well demarcated. Histologically, there were numerous variably sized, dilated ducts lined by tall columnar mucinous cells surrounded by a stroma that exhibited foci of cellular condensations resembling primitive pancreatic mesenchyme. Acinar and endocrine cells were often seen budding into the ducts forming "ductulo-insular bodies." As a result of its superficial resemblance to Stocker type 2 cystic adenomatoid malformation of the lung, we are proposing the name "multicystic adenomatoid hamartoma" for this lesion.