Molecular profiling and identification of prognostic factors in Chinese patients with small bowel adenocarcinoma.

Small bowel adenocarcinoma (SBA) is a rare malignancy with a poor prognosis and limited treatment options. Despite prior studies, molecular characterization of this disease is not well defined, and little is known regarding Chinese SBA patients. In this study, we conducted multigene next-generation sequencing and 16S ribosomal RNA gene sequencing on samples from 76 Chinese patients with surgically resected primary SBA. Compared with colorectal cancer and Western SBA cohorts, a distinctive genomic profile was revealed in Chinese SBA cohorts. According to the levels of clinical actionability to targetable alterations stratified by OncoKB system, 75% of patients harbored targetable alterations, of which ERBB2, BRCA1/2, and C-KIT mutations were the most common targets of highest-level actionable alterations. In DNA mismatch repair-proficient (pMMR) patients, significant associations between high tumor mutational burden and specific genetic alterations were identified. Moreover, KRAS mutations/TP53 wild-type/nondisruptive mutations (KRASmut /TP53wt/non-dis ) were independently associated with an inferior recurrence-free survival (hazard ratio [HR] = 4.21, 95% confidence interval [CI] = 1.94-9.14, P < .001). The bacterial profile revealed Proteobacteia, Actinobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Cyanobacteria were the most common phyla in SBA. Furthermore, patients were clustered into three subgroups based on the relative abundance of bacterial phyla, and the distributions of the subgroups were significantly associated with the risk of recurrence stratified by TP53 and KRAS mutations. In conclusion, these findings provided a comprehensive molecular basis for understanding SBA, which will be of great significance in improving the treatment strategies and clinical management of this population.

One patient with double lymphomas: simultaneous gastric MALT lymphoma and ileal diffuse large B-cell lymphoma.

Multiple different lymphomas in a single person are very rare. The author herein reports the case of a 69- year-old Japanese woman with double gastrointestinal lymphoma. The patient presented with epigastralgia. Endoscopic examination revealed erosions and elevation of the gastric body and a large ulcerated tumor of the terminal ileum. Biopsies were obtained from these lesions. The gastric lesion was MALT lymphoma with monocytoid B-cell proliferation and lymphoepithelial lesions. Light chain restriction was present. Helicobacter pylori were present on Giemsa stain. The gastric lesions did not regress despite of therapy, which were confirmed by follow-up biopsy. The ileal lesion was obvious diffuse large B-cell lymphoma. The lesion regressed by chemotherapy. The patient is now alive 3 years after the first presentation.

Role of Helicobacter pylori in the pathogenesis of complications of Meckel's diverticula.

OBJECTIVE: To assess the possible role of colonisation of ectopic gastric mucosa in Meckel's diverticula by Helicobacter pylori in causing inflammation, ulceration, perforation and bleeding. DESIGN: Retrospective study. SETTING: Three hospitals in Amsterdam, The Netherlands. MATERIAL: Specimens of 65 diverticula, 49 of which had been resected incidentally, and 16 of which had been thought to be the presenting feature. MAIN OUTCOME MEASURE: The presence of H. pylori in gastric mucosa. RESULTS: 19 Diverticula contained ectopic tissue, 18 gastric and one pancreatic tissue. Gastric tissue was found in 10 of the diverticula removed incidentally, and 8 of those that were thought to be symptomatic. In 5 of the 8 there were signs of complications that might have been related directly to the presence of gastric tissue (perforation--n = 3; bleeding--n = 1; and peptic stenosis--n = 1), and none contained H. pylori. H. pylori was found in only one of the 18 diverticula, in which there were also signs of gastritis. CONCLUSION: H. pylori has no role in the pathogenesis of the complications of Meckel's diverticula.

Electron microscopy of intestinal adenomatosis in the blue fox, Alopex lagopus.

Scanning electron microscopy of adenomatous intestinal tissue in the blue fox revealed an irregular surface topography of the colon with increased diameter of the crypt openings and prominent ridge formations between crypts. The ileum showed villous atrophy and fusion. Microvilli were short and irregular. Small ulcerations of intestinal mucosa were seen. Freeze-fracture revealed curved intracellular organisms in the altered epithelial cells. Transmission electron microscopy showed features associated with immaturity and high protein synthesis. Filamentous extensions from the basolateral plasma membrane of altered epithelial cells sometimes penetrated the basal lamina. The cytoplasm contained numerous polyribosomes, nuclei had many indentations and large and irregular nucleoli. Intracellular bacteria, with morphology corresponding to Campylobacter spp. were found in the apical epithelial cytoplasm. No host-cell-derived membrane was seen to surround the bacteria.

Campylobacter-like organisms and heterotopic gastric mucosa in Meckel's diverticula.

To assess the possibility that Campylobacter pylori might colonise heterotopic gastric mucosa a detailed histological review of 69 cases of Meckel's diverticula resected over 17 years was undertaken. Twenty three were resected incidentally while 46 were excised as the suspected cause of symptoms. Gastric mucosa was found in 13 diverticula (19%), 10 from the symptomatic group and three from the incidental cases, of which eight showed active gastritis affecting the heterotopic mucosa. Specific staining showed spiral bacteria with the typical morphology of C pylori adherent to gastric mucosa in four of the diverticula showing active gastritis. Campylobacter-like organisms were not seen on normal heterotopic gastric mucosa or on adjacent intestinal epithelium. The findings show that Campylobacter-like organisms, identical in appearance, staining, and distribution with C pylori, colonise and possibly inflame heterotopic gastric mucosa in Meckel's diverticulum.

Porcine intestinal adenomatosis: epithelial dysplasia and infiltration.

Occasionally in cases of porcine intestinal adenomatosis (PIA) epithelial dysplasia is seen with infiltration of the epithelium into underlying tissues and spread, via the lymphatics, to drainage lymph nodes. The intracellular bacterium Campylobacter sputorum subspecies mucosalis, associated with PIA, can be demonstrated in the epithelial cells of the metastases. This dysplasia and infiltration appears to be related to surface damage and inflammation.