Malignant pleural mesothelioma is a refractory tumor with poor prognosis associated with asbestos exposure. Pleural effusion is frequently observed in patients with malignant pleural mesothelioma, and cytological analysis is effective to detect malignant pleural mesothelioma. However, cytological discrimination between malignant pleural mesothelioma and reactive mesothelium is often difficult. Increased expression of CD146, a cell adhesion molecule, has been reported to be closely associated with an advanced stage of malignant melanoma, prostate cancer, and ovarian cancer. In this study, to evaluate the diagnostic utility of CD146 for discrimination between malignant pleural mesothelioma and reactive mesothelium, we examined immunocytochemical expression of CD146 in malignant pleural mesothelioma and reactive mesothelium using two clones of CD146 antibody, OJ79 and EPR3208, on smear specimens of effusion fluids. Immunocytochemical stains were semiquantitatively scored on the basis of immunostaining intensity (0, negative; 1, weak positive; 2, moderate positive; and 3, strong positive). CD146 expression was detected in 15 of 16 malignant pleural mesothelioma with median immunostaining score of 3 by OJ79, and in 19 of 21 malignant pleural mesothelioma with median immunostaining score of 2 by EPR3208. Strong immunoreactivity of CD146 was observed at the apposing surfaces of cell-cell interactions on the plasma membrane of mesothelioma cells. In addition, one OJ79-negative case of malignant pleural mesothelioma was positive for CD146 by EPR3208 and two EPR3208-negative cases of malignant pleural mesothelioma were CD146 positive by OJ79, showing that all 23 malignant pleural mesothelioma cases were positive for CD146 by either OJ79 or EPR3208. On the other hand, CD146 expression was undetectable in all reactive mesothelium cases by OJ79 and EPR3208. The sensitivity of OJ79 and EPR3208 was 94 and 90%, respectively, and the specificity was 100% for both clones. We propose that CD146 is a sensitive and specific immunocytochemical marker enabling differential diagnosis of malignant pleural mesothelioma from reactive mesothelium.

BackgroundGangliocytic paraganglioma (GP) is an extremely rare benign tumor that commonly arises from the second part of the duodenum. Since GP exhibit neither prominent mitotic activity nor Ki-67 immunoreactivity, this tumor is often misdiagnosed as neuroendocrine tumor (NET) G1 (carcinoid tumor). However, patients with GP may have a better prognosis than patients with NET G1. This fact emphasizes the importance of differentiating GP from NET G1, but few studies have reported the epidemiology and histopathology of GP because of its rarity. To differentiate GP from NET G1 with ease, we conducted a multi-institutional retrospective study analyzing the morphometric and immunohistochemical features of this tumor.MethodsSince only a limited number of patients with GP could be identified in our institute, we conducted a multi-institutional retrospective study of GP in Japan, which was approved by the Ethics Committee of our medical institute. The obtained tissue sections underwent detailed morphometric and immunohistochemical analyses. Additionally, to differentiate GP from NET G1 with ease, immunohistochemical findings were compared.ResultsIn our examination of 12 cases of duodenal GP, we found that epithelioid cells of GP exhibited positive reactivity for progesterone receptor and pancreatic polypeptide, whereas tumor cells of NET G1 were completely negative reactivity for both. Additionally, although GP is considered to be an extremely rare NET, we found that four (40.0%) of the ten patients at our institute with duodenal NET G1 actually had GP.ConclusionsAlthough GP is regarded as a rare NET, our results suggest that it accounts for a substantial percentage of duodenal NETs. Additionally, confirmation of immunoreactivity for progesterone receptor and pancreatic polypeptide can assist in differentiating GP from NET G1.

Background. The mode of tumor growth of intrahepatic cholangiocarcinoma (CC) varies considerably from patient to patient. This study describes the clinicopathologic variety of the extraductal mass‐forming type of CC. Methods. Patients with CC characterized by an extraductal mass (n = 26) who underwent hepatectomy from 1976 through 1992 were clinicopathologically classified into three types: Type I (n = 7), no biliary stricture; Type II (n = 13), biliary stricture without jaundice; and Type III (n = 6), biliary stricture with jaundice. Results. Type I included three patients with microductular‐trabecular arrangement and behavior reminiscent of hepatocellular carcinoma (high association with chronic liver disease, mild positivity for alpha‐fetoprotein [AFP], no lymph node metastasis, but frequent intrahepatic metastasis), in contrast to the other typical cholangiocarcinoma. Hepatolithiasis was associated only with Type II CC. The serum positivity for AFP and carcinoembryonic antigen was much higher in Type I CC, whereas positivity of CA 19‐9 was highest in Type III. Involvement of the portal vein, hepatic artery, or hepatic duct was most frequent in Type III CC, which necessitated resection of the extrahepatic bile duct and hepatectomy. Conclusion. The clinicopathologic behavior of intrahepatic CC differs considerably according to the presence or absence of stricture of the biliary tree. Thus, CC without biliary stricture behaves more like hepatocellular carcinoma, whereas CC with biliary stricture is more like hilar or extrahepatic bile duct carcinoma.

It is important to study the effect of Helicobacter pylori infection on the permeability of the intestine. Permeability was evaluated by oral sucrose tolerance test using sucrose 25 g in 200 ml of water. Existence of H. pylori itself was associated with increased permeability of sucrose. Also, the permeability of sucrose increased as polymorphonuclear and lymphocyte infiltration increased. The increase of mucosal permeability suggests that antigens like protein penetrate into the body and result in systemic reactions. Thus, it is important to study the implication of increased permeability in relation not only to gastric diseases but also certain systemic diseases.

A rare case of retroperitoneal ganglioneuroma incidentally found during an annual health examination is presented. The patient was an asymptomatic female, age 26. Physical examination and routine laboratory studies gave normal results. The plasma concentrations and 24-h urinary excretion of catecholamine and its metabolites were within the normal range. The patient was diagnosed as having a left supra-renal mass (6.3 X 3.6 cm) by abdominal ultrasono graphy, although by image diagnosis the paraadrenal mass could not be discriminated from an adrenal tumor. Operation was performed under the suspicion of a nonfunctioning adrenal tumor. The tumor removed was 8 X 6 X 4cm, 98g and was encapsulated. Histopathological diagnosis of retroperitoneal ganglioneuroma was confirmed. Forty-one cases of retroperitoneal ganglioneuroma in the Japanese literature including the present case are reviewed. (Internal Medicine 31: 82-85, 1992)

We experienced a very rare case of ulcerative colitis (UC) accompanied with analogous lesions in the stomach, duodenum, and ileal J-pouch. Ileal J-pouch anal anastomosis was performed on a 29-year old woman in 1996. Six years later, she was admitted again to our hospital because of epigastralgia, nausea, watery diarrhea and low fever. Based on the results of endoscopic examination, we diagnosed it as pouchitis. Moreover, on hypotonic duodenography, expansion of the duodenal bulb and the descending portion were poor. Kerckring folds disappeared with typical lead-pipe appearance. The pathogenesis of the gastric and duodenal lesion in this patient was similar to that of the colonic lesions of UC. For the gastroduodenal lesions in this patient, symptomatic remission was obtained following administration of crushed mesalazine tablets (1500 mg/d) for 14 d with continuous administration of omeprazole. Firstly we used ciprofloxacin to treat pouchitis. On the fifth day, she got a fever because of catheter infection. In the catheter culture, methicillin-resistant Staphylococcus aureus (MRSA) was detected. Therefore we changed ciprofloxacin to vancomycin hydrochloride (Vancomycin). Vancomycin was very effective, and the stool frequency dramatically improved in three days. Now she continues to take mesalazine, but her condition is stable and there has been no recurrence of pouchitis.

A classical carcinoid tumor, measuring ll x 17 mm, was found in a 41-year-old womanin the neck of the gall bladder. The lesion infiltrated the muscular layer of the gall bladder wall. Histologically, the tumor was positive for only Grimelius and chromogranin A stains. In a literature search, approximately half of the tumors reported as gall bladder carcinoid tumor appear to be actually endocrine cell carcinomas, which are completely different from classical carcinoid tumors with respect to size, metastasis and prognosis. These carcinomas should not be termed as carcinoid tumors from both the clinical and histological points of view, and should be clearly distinguished from benign lesions whenreported. (Internal Medicine 35: 953-956, 1996)

CEUS with Sonazoid is a powerful evaluation tool to diagnose NASH from an early stage of the disease.