Gastric neuroendocrine carcinoma staged and followed with (18)F-FDG PET/CT--a report of 3 cases.

Gastric neuroendocrine carcinomas (NEC) are very rare, aggressive tumors of the stomach that are distinct from the more benign neuroendocrine tumors, sometimes referred to as "gastric carcinoids." We present 3 cases of gastric NEC representing various histological subtypes that were successfully staged and followed with F-FDG PET/CT, impacting therapeutic management in each case.

Duodenal gastrinoma with multiple gastric neuroendocrine tumors secondary to chronic Helicobacter pylori gastritis.

Helicobacter pylori (HP) has been associated with neuroendocrine tumors of the stomach and duodenum. Gastric enterochromaffin-like (ECL) cell tumors and duodenal gastrinomas have also been associated with HP gastritis in separate series but have not been reported together. With other possible causes excluded, we present a patient with HP-associated atrophy of the oxyntic mucosa that ultimately resulted in stimulation and reactive hyperplasia of gastrin-producing cells in both the antrum and proximal duodenum, the latter progressing to formation of a gastrin-producing cell nodule (gastrinoma). Both of these sources of gastrin resulted in ECL hyperplasia in the atrophied oxyntic mucosa with progression to microcarcinoids and well-differentiated neuroendocrine tumors, along with hypertrophy of residual proximal gastric parietal cells. As atrophy tends to spread from the antrum proximally, residual oxyntic mucosa was still infected with HP and offers 1 explanation for the apparent paradox of atrophic gastritis with ECL hyperplasia and neoplasia in the distal oxyntic mucosa, with proximal oxyntic mucosa showing mild hypertrophic changes in a background of typical HP gastritis.

Common biostructure of the colonic microbiota in neuroendocrine tumors and Crohn's disease and the effect of therapy.

BACKGROUND: The aims were to comparatively investigate the biostructure of colonic microbiota in patients with neuroendocrine tumors and Crohn's disease (CD) and to study the response of the microbiota to therapy. METHODS: Sections of fecal cylinders from 66 patients with neuroendocrine tumors (NET; 25 foregut, 30 midgut, 11 hindgut), 50 patients with CD (Crohn's Disease Activity Index [CDAI] ≥150), and 30 patients with chronic idiopathic diarrhea seen at the Charité Hospital and 25 healthy controls were investigated using fluorescence in situ hybridization with probes specific for five bacterial groups: Faecalibacterium prausnitzii, Clostridium group XIVa / Roseburia group, Bacteroides, Enterobacteriaceae, and Bifidobacteriaceae. RESULTS: We found a striking F. prausnitzii (Fprau) depletion in the stool of patients with NET of the midgut and patients with CD. The changes of the microbiota in the two other NET groups were uncharacteristic and similar to those observed in patients with chronic idiopathic diarrhea. Fprau depletion was reversible with chemotherapy and with interferon alpha-2b treatment in patients with midgut NET. Somatostatin analogs had no influence on Fprau concentrations. CONCLUSIONS: Patients with NET and CD show similarities in their abnormalities of the fecal biostructure. Interferon alpha and systemic chemotherapy significantly improved the fecal biostructure in patients with midgut NET.