Predictive factors for esophageal stenosis after endoscopic submucosal dissection for superficial esophageal cancer

Endoscopic submucosal dissection (ESD) has been utilized as an alternative treatment to endoscopic mucosal resection for superficial esophageal cancer. We aimed to evaluate the complications associated with esophageal ESD and elucidate predictive factors for post-ESD stenosis. The study enrolled a total of 42 lesions of superficial esophageal cancer in 33 consecutive patients who underwent ESD in our department. We retrospectively reviewed ESD-associated complications and comparatively analyzed regional and technical factors between cases with and without post-ESD stenosis. The regional factors included location, endoscopic appearance, longitudinal and circumferential tumor sizes, depth of invasion, and lymphatic and vessel invasion. The technical factors included longitudinal and circumferential sizes of mucosal defects, muscle disclosure and cleavage, perforation, and en bloc resection. Esophageal stenosis was defined when a standard endoscope (9.8 mm in diameter) failed to pass through the stenosis. The results showed no cases of delayed bleeding, three cases of insidious perforation (7.1%), two cases of endoscopically confirmed perforation followed by mediastinitis (4.8%), and seven cases of esophageal stenosis (16.7%). Monovalent analysis indicated that the longitudinal and circumferential sizes of the tumor and mucosal defect were significant predictive factors for post-ESD stenosis (P < 0.005). Receiver operating characteristic analysis showed the highest sensitivity and specificity for a circumferential mucosal defect size of more than 71% (100 and 97.1%, respectively), followed by a circumferential tumor size of more than 59% (85.7 and 97.1%, respectively). It is of note that the success rate of en bloc resection was 95.2%, and balloon dilatation was effective for clinical symptoms in all seven patients with post-ESD stenosis. In conclusion, the most frequent complication with ESD was esophageal stenosis, for which the sizes of the tumor and mucosal defect were significant predictive factors. Although ESD enables large en bloc resection of esophageal cancer, practically, in cases with a lesion more than half of the circumference, great care must be taken because of the high risk of post-ESD stenosis.

Expression of UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferase isozymes T1 and T2 in human colorectal cancer

Uridine diphosphate (UDP)-GalNAc: polypeptide N-acetylgalactosaminyltransferase (GalNAc transferase) catalyzes the initial step in mucin type O-glycosylation, and its expression has been assumed to be altered between normal epithelial cells and cancer cells. We studied the alteration of GalNAc transferase expression during the carcinogenesis of human colorectal epithelial cells. We produced polyclonal antibodies against synthetic polypeptides with specific sequence to two GalNAc transferase isozymes, T1 and T2. Surgically resected specimens from 50 patients with colorectal cancer were immunohistochemically stained, and the staining grade (percentage of positively stained cells) was compared between cancer and its normal counterpart in the same specimen. Significant signals for both T1 and T2 expression were seen in the supranuclear region of normal and cancer cells, indicating the subcellular localization of the enzymes in the Golgi apparatus. The prevalence of positive staining for T1 and T2 expression in colorectal cancer was significantly higher than that in normal epithelium (P < 0.05). However, the difference in staining grades between cancer and normal tissues varied in each patient. These results indicate that there is variability in the expression patterns of GalNAc transferase isozymes in normal and cancerous cells colorectal among individuals.

A Discrepant Finding Between Magnetic Resonance Imaging and Other Imaging Modalities Suggests a Microcystic Serous Cystadenoma of the Pancreas

BACKGROUND

Serous cystadenoma of the pancreas is generally considered as having no malignant potential. Thus, of clinical importance is a differential diagnosis of this neoplasm from other solid tumors that are often malignant.

RESULTS

We report a case of microcystic serous cystadenoma of the pancreas. Abdominal ultrasonography, computed tomography, and endoscopic ultrasonography showed a solid mass in the body of the pancreas with a diameter of 15 mm, but magnetic resonance imaging revealed it as a unilocular cystic lesion. Histological examinations on the surgically resected tissue specimen showed a honeycombed tumor with innumerable tiny cysts appearing grossly as a solid mass. The discrepant finding between magnetic resonance imaging and other imaging modalities observed in this case is suggestive of and might be specific to microcystic serous cystadenoma of the pancreas.

CONCLUSIONS

Magnetic resonance imaging is a mandatory modality to identify pancreatic serous cystadenoma that contains no visible cystic compartments on computed tomography and ultrasonography.

Endosonography-guided endoscopic resection of duodenal carcinoid tumor

Endoscopic resection techniques using snare polypectomy with or without submucosal saline injection have also been applied to resect smaller duodenal carcinoid tumors. We report on two patients where endoluminal ultrasound using a small diameter probe was used to visualize the adherence of the carcinoids to the underlying wall layers and the separating effect of subtumoril saline injection. One patient, in whom a clear separation between the tumor and the underlying tissue after saline injection was visualized, underwent successful endoscopic resection. In the other patient no clear separation could be achieved after saline injection and the patient underwent surgical removal of his tumor; both tumors were 1 cm or less in their maximal diameter.