Duodenal stenosis caused by ruptured aneurysms of the pancreaticoduodenal artery--a case report.

A case reported herein is a patient with ruptured minute pancreaticodudenal arterial aneurysms that proved difficult to distinguish from malignant tumors of the pancreas or duodenum. A 61-year-old woman was admitted to our hospital complaining of abdominal fullness, epigastralgia, nausea, and vomiting. Pre-operative examinations demonstrated duodenal stenosis, mass formation in the head of the pancreas, and three tiny aneurysms in the branches of the gastroduodenal artery. At surgery, an orange-sized mass was revealed in the head of the pancreas, which had adhered fibrously to the duodenum, inferior vena cava, and transverse mesocolon. Thus, pancreaticoduodenectomy was performed with a tentative diagnosis of a malignant tumor of the pancreas or duodenum. Subsequent histopathologic examinations, however, demonstrated the presence of a hematoma between the pancreas and duodenum, extensive fibrosis around the hematoma and dissecting aneurysms in the branches of the pancreaticoduodenal artery. In this case, it was considered that fibrosis around the ruptured aneurysms extending to the surrounding organs made it difficult to distinguish the aneurysms from a malignant tumor.