UNASSIGNED: Gastric adenocarcinoma can present uncommonly. This emphasizes the need for intensified vigilance in the absence of typical gastrointestinal symptoms, particularly in areas where infectious diseases are common.
UNASSIGNED: Gastric adenocarcinoma, a common advanced-age global malignancy is typically associated with abdominal symptoms. However, atypical presentations such as back pain and respiratory distress particularly in younger patients represent diagnostic challenges. We present a case of a late-30s male who presented initially with back pain, shortness of breath, and constitutional symptoms. A diagnosis of tuberculosis was established presumptively with immediate initiation of treatment. Later on, he presented with abdominal pain and intractable vomiting. Oesophagoduodenoscopy (OGD), tissue histology, and immunohistochemistry confirmed a diffuse type gastric adenocarcinoma. He died as a result of complications from an advanced disease. This particular instance emphasizes the importance of maintaining a high index of skepticism even in atypical presentations, as well as the significance of prompt OGD alongside potential genetic testing if any. Gastric adenocarcinoma should be contemplated by clinicians in a variety of clinical scenarios, especially when handling younger patients from settings with limited resources to facilitate timely diagnosis and effective treatment.

BACKGROUND: Gastric adenocarcinoma is associated with H. pylori infection and inflammation that can result in the dysbiosis of gastric microbiota. The association of intestinal microbiota with gastric adenocarcinoma subtypes or with gastric gastrointestinal stromal tumors (GIST) is however not well known. Therefore, we performed 16S rRNA gene sequencing on DNA isolated from stool samples of Finnish patients and controls to study differences in microbiota among different histological subtypes of gastric adenocarcinoma, gastric GIST and healthy controls.
RESULTS: We found that gut microbiota alpha diversity was lowest in diffuse adenocarcinoma patients, followed by intestinal type and GIST patients, although the differences were not significant compared to controls. Beta-diversity analysis however showed significant differences in microbiota composition for all subtypes compared to controls. Significantly higher abundance of Enterobacteriaceae was observed in both adenocarcinoma subtypes, whereas lower abundance of Bifidobacteriaceae was seen only in diffuse adenocarcinoma and of Oscillibacter in intestinal adenocarcinoma. Both GIST and adenocarcinoma patients had higher abundance of Enterobacteriaceae and lower abundance of Lactobacillaceae and Oscillibacter while lower abundance of Lachnoclostridium, Bifidobacterium, Parabacteroides and Barnesiella was seen only in the adenocarcinoma patients.
CONCLUSIONS: Our analysis shows association of higher Enterobacteriaceae abundance with all types of gastric tumors. Therefore it could be potentially useful as a marker of gastric malignancies. Lower gut microbiota diversity might be indicative of poorly differentiated, invasive, advanced or aggressive tumors and could possibly be a prognostic marker for gastric tumors.

BACKGROUND: Gastric hyperplastic polyps are common stomach lesion and these polyps are generally benign. However, they can undergo malignant transformation. Most reported cases of malignant transformation of gastric hyperplastic polyps have been to well or moderately differentiated adenocarcinoma, and those transformed into poorly differentiated adenocarcinoma are extremely rare. No case has been reported that has changed to diffuse type adenocarcinoma with lymphatic invasion.
METHODS: A 48-year-old woman presented with worsening anemia. A polyp was seen in the gastric cardia seven years prior to presentation. Helicobacter pylori infection was also found at that time. She underwent upper gastrointestinal endoscopy and biopsy of the polyp revealed signet ring cell carcinoma. Total gastrectomy was performed due to concern about possible invasion into the submucosal layer and there was no evidence of distant metastases. Histologic examination revealed both poorly differentiated adenocarcinoma and signet ring cell carcinoma surrounded by hyperplastic epithelium at the head of the polyp. Lymphatic invasion was also found, and malignant cells were limited to the mucosa.
CONCLUSIONS: Gastric hyperplastic polyps are commonly associated with chronic gastritis which is related to Helicobacter pylori infections. Gastric hyperplastic polyps are generally benign and rarely undergo malignant transformation to adenocarcinoma with differentiated histology. The gastric hyperplastic polyp in this patient transformed to poorly differentiated adenocarcinoma with lymphatic invasion.
CONCLUSIONS: Even small polyps may become poorly differentiated adenocarcinoma with invasion, so close follow-up or endoscopic resection are recommended as well as eradication of Helico Pylori infection when appropriate.