Endoscopic Manifestations and Clinical Characteristics of Localized Gastric Light-Chain Amyloidosis.

To determine the endoscopic and clinical features of localized gastric amyloid light-chain (AL) amyloidosis, we retrospectively examined the characteristics of nine patients (eight men and one woman) encountered by the hospitals in our network. Lesions were predominantly flat and depressed with surface vascular dilatation (n=5); others were characterized by subepithelial lesions (n=2), mucosal color change (n=1), and a mass-like morphology with swollen mucosal folds (n=1). Colonoscopy (n=7), video capsule enteroscopy (n=2), serum (n=5) and urine immunoelectrophoresis (n=4), and bone marrow examination (n=3) were performed to exclude involvement of organs other than the stomach. As treatment for gastric lesions of AL amyloidosis, one patient each underwent endoscopic submucosal dissection (n=1) and argon plasma coagulation (n=1), while the remaining seven patients underwent no specific treatment. During a mean follow-up of 4.2 years, one patient died 3.2 years after diagnosis, but the cause of death, which occurred in another hospital, was unknown. The remaining eight patients were alive at the last visit. In conclusion, although localized gastric AL amyloidosis can show various macroscopic features on esophagogastroduodenoscopy, flat, depressed lesions with vascular dilatation on the surface are predominant.

Gastric MALT Lymphoma with Increased Plasma Cell Differentiation Showing Unique Endoscopic Features.

A 62-year-old woman was diagnosed with extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with increased plasma cell differentiation of the stomach. Esophagogastroduodenoscopy showed slightly elevated, whitish lesions in the gastric body. Magnifying endoscopic observation revealed that the gastric surface epithelium was swollen, but the structure was not destroyed or diminished. Elongated, tortuous vasculature was observed on the surface of the whitish lesions. The patient underwent eradication treatment for Helicobacter pylori, which resulted in complete remission. Although the appearance of abnormal vessels and the destruction of gastric epithelial structure are the typical features of gastric MALT lymphoma during magnifying endoscopy, the present case showed different features, which were rather similar to those observed in a previously reported case of gastric plasmacytoma. The current case indicates that magnifying endoscopic features are not uniform among gastric MALT lymphomas.

Whipple's Disease with Long-term Endoscopic Follow-up.

A 72-year-old man presented with anorexia and 15-kg weight loss over 3 years. Endoscopy revealed yellow, shaggy mucosa alternating with erythematous, eroded mucosa in the duodenum. Biopsy specimens showed massive infiltration of periodic acid-Schiff-positive macrophages in the lamina propria, consistent with Whipple's disease. The patient was treated with intravenous ceftriaxone for four weeks, followed by oral trimethoprim-sulfamethoxazole. His condition improved, and he gradually gained weight. Although the endoscopic findings improved with continuous trimethoprim-sulfamethoxazole administration, macrophage infiltration of the duodenal mucosa persisted. However, the patient has been symptom-free for eight years.

Ectopic pancreas in the stomach successfully resected by endoscopic submucosal dissection.

A 32-year-old Japanese man presented with a gastric submucosal tumor. Esophagogastroduodenoscopy showed a sessile submucosal tumor measuring approximately 10 mm in diameter on the greater curvature of the gastric antrum. Endoscopic ultrasonography examination revealed a solid tumor with a diameter of 11.8 mm, which was located in the deep mucosal and submucosal layers. The internal echogenicity was homogenous and hypoechoic. Biopsy examinations were performed twice but were not diagnostic since only the intact mucosal layer was obtained. The patient was subsequently diagnosed with ectopic pancreas in the stomach by endoscopic submucosal dissection (ESD). This case underscores the usefulness of the ESD technique for the pathological diagnosis of gastric submucosal tumors.

Improvements in the measurement of stool decay-accelerating factor in the detection of colorectal cancer.

We have previously developed an enzyme-linked immunosorbent assay (ELISA) to measure stool decay-accelerating factor (DAF) and found that stool DAF concentrations were significantly elevated in patients with colorectal cancer, suggesting that the measurement of stool DAF may be valuable for the detection of colorectal cancer. In order to refine the assay for the measurement of stool DAF, we investigated 1) effects of centrifugation of stool samples, 2) effects of detergents, and 3) adequate combination of various anti-DAF monoclonal antibodies for the ELISA system using only monoclonal antibodies. We found that high-speed centrifugation could be omitted and that only the removal of large undigested food residues by centrifugation of short duration in a low-speed benchtop microcentrifuge sufficed to adequately prepare the stool samples. Addition of 2 detergents, octyl beta-glucoside and sodium deoxycholate, known to solubilize glycosyl-phosphatidylinositol-anchored proteins such as DAF, did not influence stool DAF values. By using 2 mouse anti-DAF monoclonal antibodies (clone 4F11 and 1C6), we were able to achieve a stable ELISA for the measurement of stool DAF using a uniform source of antibodies. The results should allow us to consistently apply the DAF assay for routine use in the detection of colorectal cancer.