Yasuhide Ishikawa

Xanthogranulomatous pancreatitis mimicking a malignant cystic tumor of the pancreas: Report of a case

Xanthogranulomatous pancreatitis (XGP) is a rare inflammatory disease of the pancreas. A correct diagnosis is usually made only after pathological examination. A 76-year-old man was referred to our hospital for investigation of erythroderma, muscle weakness, and weight loss. We suspected dermatomyositis as a paraneoplastic phenomenon and investigated accordingly. Computed tomography showed a cystic lesion encapsulated by a thick wall in the pancreatic body. On magnetic resonance imaging, the lesion had low intensity on the T1-weighted images and heterogeneously high intensity on the T2-weighted images. 18F-Fluorodeoxyglucose positron emission tomography showed abnormal uptake with a maximum standardized uptake value of 9.1. Based on these findings, we made a preoperative diagnosis of intraductal papillary-mucinous carcinoma and performed a distal pancreatectomy. Macroscopically, the cyst was surrounded by a yellow-tan mass with an unclear border, and was filled with hemorrhagic and necrotic tissue. Microscopically, the mass contained an aggregation of many foamy histiocytes, lymphocytes, and plasma cells. These microscopic findings were consistent with xanthogranulomatous inflammation, and the lesion was diagnosed as XGP. Although it is a rare benign pancreatic lesion, XGP should nevertheless be considered in the differential diagnosis of cystic lesions of the pancreas.

Mucosal necrosis of the small intestine in myopathy, encephalopathy, lactic acidosis, and stroke-like episodes syndrome

This report presents a case of massive mucosal necrosis of the small intestine in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), which particularly affects the brain, nervous system and muscles. A 45-year-old Japanese female, with an established diagnosis of MELAS, presented with vomiting. Computed tomography showed portomesenteric venous gas and pneumatosis intestinalis. She underwent a resection of the small intestine. A microscopic study showed necrosis of the mucosa and vacuolar degeneration of smooth muscle cells in the arterial wall. Immunohistochemistry showed anti-mitochondrial antibody to be highly expressed in the crypts adjacent the necrotic mucosa. The microscopic and immunohistochemical findings suggested the presence of a large number of abnormal mitochondria in MELAS to be closely linked to mucosal necrosis of the small intestine.

Adenocarcinoma in an intrapancreatic accessory spleen: Report of a case

We report a case of adenocarcinoma in an intrapancreatic accessory spleen (IPAS). A 78-year-old woman presented with abdominal discomfort, and investigations revealed an elevated serum carbohydrate antigen 19-9 level, to 161.8 U/ml (normal, <37 U/ml). Ultrasonography showed a heterogeneous echogenic tumor with a vascular hilum. Computed tomography showed a heterogeneously enhanced tumor, 8 cm in diameter, adjacent to the pancreatic body, accompanying a feeding artery arising from the splenic artery, and a drainage vein flowing into the splenic vein. We performed a distal pancreaticosplenectomy. The tumor was surrounded by a fibrous capsule and was in contact with the pancreatic body. Histological examinations revealed invasive growth of adenocarcinoma in a structure identical to the spleen. The results of both radiological and histological examinations suggested that the tumor originated from an intrapancreatic accessory spleen. Extensive examinations revealed no other malignancy, based on which we concluded that the adenocarcinoma was primary. Surgical intervention is strongly recommended when a malignancy in an IPAS cannot be ruled out.