Munemasa Ryu

Cholangiocarcinoma arising in bile duct adenoma with focal area of bile duct hamartoma

A 59-year-old male with history of sigmoid colon cancer had a high serum-CEA level and was referred for the evaluation of metastatic liver disease. Ultrasonography and computerized tomography showed two tumours in the liver. Macroscopically, these were in segment 4 (S4) and 2 (S2). Histologically, the tumour in S4 showed a number of bile ductules with variable amounts of stroma, an appearance compatible with bile duct adenoma (BDA). There were markedly atypical ductules of various sizes, the epithelium of which had coarsely granular/hyperchromatic large nuclei, in some areas of the lesion. These atypical ductules showed invasive growth into the liver parenchyma. Some cystically dilated ductules with bile plugs resembling bile duct hamartoma (BDH) were also seen. The other tumour in S2, was a metastatic adenocarcinoma from sigmoid colon and showed strongly positive staining for CEA. Since the lesion in S4 of our case is solitary and most of histological features are similar to those of BDA with markedly atypical bile ductules, we consider that this may be the first case of cholangiocarcinoma associated with BDA with focal area of BDH. It is possible that the adenoma-carcinoma sequence occurs in biliary tumours.

Peroral Pancreatoscopy for the Diagnosis of Pancreatic Diseases

The efficacy associated with peroral pancreatoscopy to diagnose and differentiate pancreatic diseases is herein reviewed and clarified, and problems with this modality are discussed. Three types of pancreatoscopes are presently available: (a) a thin fiberscope with a diameter of 3.3 or 4.5 mm, which has an angulation system and a forceps channel; (b) an ultrathin pancreatoscope with a diameter of 0.75 or 0.8 mm, which can be inserted via an ordinary endoscopic retrograde cholangiopancreatography (ERCP) cannula without endoscopic sphincterotomy; and (c) an ultrathin pancreatoscope combined with a catheter that has an outer diameter of 1.67 mm. Peroral pancreatoscopy facilitates the detection of small lesions of the duct in malignancy or chronic pancreatitis. In particular, it is quite useful in differentiating pancreatic cancer from chronic pancreatitis in cases with local stenosis or elevated lesions of the main pancreatic duct. Among patients with a mucus-producing tumor of the pancreas, pancreatoscopy is also very useful, especially in determining lesion extent. Despite some unresolved problems, we predict that pancreatoscopy will retain a limited or specific and definite role in diagnostic and therapeutic endoscopy for pancreatic diseases.

Expression of Integrin α3 in Gastric and Colorectal Cancers: Its Relation to Wall Contraction and Mode of Invasion

We macroscopically classified 25 gastric and 23 colorectal advanced cancers into “contracted” and “uncontracted” types, and found immunohistochemically that integrin subunit α3 was more frequently expressed in the extracellular matrix (ECM) in the former than in the latter (75%:9/12 vs. 38%: 5/13 in gastric and 86%:6/7 vs. 25%:4/16 in colorectal cancers, respectively). Integrin subunit α3 was also expressed more frequently in cancers producing transforming growth factor‐beta (TGF‐β), which is related to ECM deposition, integrin expression and cell mobility, than in those which did not produce TGF‐β (67%:10/15 vs. 40%:4/10 in gastric and 57%:4/7 vs. 38%:6/16 in colorectal cancers, respectively). In addition, integrin subunit α3 was not expressed in 2 benign gastric ulcers combined with gastric cancer elsewhere in the stomach. On the other hand, a retrospective analysis of 107 cases of rectal cancer which recurred after a curative operation revealed that local recurrence was more frequent in “contracted” than “uncontracted” types (44%:ll/25 vs. 26%:21/82). These results may suggest that the abundant interstitial fibrosis which leads to remarkable gastric or colorectal wall contraction is a result of the interaction between cancer cells and ECM, along with the expression of integrin and/or the production of TGF‐β, This fibrosis may also be closely related to the mode of gastric and colorectal cancer invasion.

Correlation Between the Depth of Invasion and Hardness of Resected Gastric Carcinoma Specimens Using a New Ultrasound Tactile Sensor

Abstract: We assessed the objective measurement of gastric wall hardness in gastric cancer specimens with a new tactile sensor. The basic principle of measuring hardness and/or softness of living tissue is based on changes in the frequency of the tactile sensor. The change in resonance frequency, Δf=fx‐fo, is the difference between the frequency of the sensor in contact with the specimen, fx, and the non‐contact frequency, fo. The change in resonance frequency increases as tissue hardness decreases. We measured hardness at 5 points in 13 fresh specimens obtained by gastrectomy and analyzed the histopathological features corresponding to each point. We found that the more deeply the tumor had invaded, the harder the cancerous areas tended to be as compared to normal areas. However, the hardness of gastric cancer areas was influenced not only by the depth of invasion, but also by tumor size, the presence of associated fibrosis within the lesion, and the tumor stroma quantity. Gastric wall hardness correlated with the depth invasion of lesions less than 40 mm in size, the absence of tumor fibrosis, and medullary type tumor extension.