Clinicopathological differences of laterally spreading tumors arising in the colon and rectum

Purpose

Laterally spreading tumors (LST) have been recognized worldwide. The aim of our retrospective study was to evaluate the clinicopathological differences of LST arising in the colon and rectum.

Methods

We investigated the clinical records of consecutive patients with LST that were endoscopically or surgically resected at our hospital between February 2006 and March 2011. LST were classified into three types: granular-homogenous (LST-GH), granular-nodular mixed (LST-GM), and nongranular (LST-NG) types. We also defined the hardly elevated flat lesion with a dilated pit pattern that occurs at the margins of LST as the “skirt.” The clinicopathological characteristics of the LST arising in the colon and rectum, including the presence of the skirt, were compared.

Results

A total of 496 colorectal LST in 435 patients were examined. LST-GM was predominant in the rectum, whereas LST-NG was predominant in the colon (p?p?p?p?Conclusions A greater proportion of LST-GM, greater mean size, and lower incidence of low-grade dysplasia were found in rectal LST. The skirt was a novel and unique finding, primarily observed in rectal LST-GM cases.     

Intestinal epithelial culture under an air‐liquid interface: a tool for studying human and mouse esophagi

This study investigated whether an intestinal epithelial culture method can be applied to mouse and human esophageal cultures. The esophagi harvested from 1‐day‐old mice and adult humans were maintained in collagen gels. A commercially available culture medium for human embryonic stem cells was used for the human esophageal culture. We discovered that the intestinal epithelial culture method can be successfully applied to both mouse and human esophageal cultures. The long‐term cultured esophageal organoids were rod‐like luminal structures lined with myofibroblasts. We discovered that regeneration of the esophageal mucosal surface can be almost completely achieved in vitro, and the advantage of this method is that organoid cultures may be generated using host‐derived fibroblasts as a niche. This method is a promising tool for mouse and human research in intestinal biology, carcinogenesis, and regenerative medicine.     

Disseminated toxoplasmosis after hematopoietic stem cell transplantation showing unusual magnetic resonance images

We herein report a patient who had disseminated toxoplasmosis after hematopoietic stem cell transplantation showing atypical clinical presentation and neuroimaging. Parkinsonism symptoms such as muscle rigidity, bradykinesia, tremor, and postural instability were initial manifestations. Magnetic resonance imaging showed diffuse symmetrical lesions of bilateral basal ganglia lacking ringed enhancement. Post‐mortem analysis revealed multiple tachyzoites of Toxoplasma gondii in the basal ganglia, mid brain, cerebellum, and cardiac muscle.     

Tips for anatomical hepatectomy for hepatocellular carcinoma by the Glissonean pedicle approach (with videos)

Couinaud described three fundamental approaches at the hepatic hilus in liver surgery. The Glissonean pedicle approach at the hepatic hilus is one of these procedures and provides anatomical hepatectomy for hepatocellular carcinoma (HCC). The Glissonean pedicle approach was introduced by Couinaud and Takasaki in the early 1980s. The key of the Glissonean pedicle approach is clamping the pedicle first, secondly confirming the territory, which includes the HCC, and finally dissecting the liver parenchyma. This procedure prevents intrahepatic metastasis of HCC, which spreads along the portal vein and improves the overall survival after surgery. Another key feature is that we do not have to consider any variations of the vascular elements in the hepatoduodenal ligament under the hilar plate. This procedure allows an approach to the tertiary branches, which feed a smaller anatomical area than Couinaud's segment. We refer to this area as a cone unit of the liver. The procedure is also available in laparoscopic hepatectomy and provides new knowledge of the surgical anatomy, especially for small anatomical liver resection in the cirrhotic liver.