A case of early-stage type 3 gastric neuroendocrine tumor in the upper body of the stomach: is endoscopic resection feasible?

Although gastric neuroendocrine tumors (NETs) are uncommon compared with gastric carcinomas, the incidence of NETs has been recently increasing. Gastric NETs are classified into three subgroups, and among these, gastrin-independent sporadic type 3 gastric NETs have a poor prognosis because of frequent lymph node or distant metastasis. We experienced a case of an early-stage type 3 gastric NET associated with lymphovascular and submucosal invasion. In a 54 year-old woman, esophagogastroduodenoscopy performed during a health screening identified an elevated lesion of the upper body of the stomach. The results of immunohistochemical analyses of endoscopic biopsy specimens obtained from the lesion were positive for chromogranin A and synaptophysin, indicating an NET. Because the patient's serum gastrin level was normal and she had no predisposing conditions for NET development, the tumor was diagnosed as a type 3 gastric NET. The patient underwent local resection of the tumor and regional lymph node dissection. The resected specimen indicated a diagnosis of type 3 gastric NET with invasion into the submucosa and lymphatic duct. This is an extremely rare case of an early-stage type 3 gastric NET. Our discussion provides insight into the pathogenesis and development of these tumors and the appropriate therapeutic strategy.

Gastric type III heterotopic pancreas presenting as adenomyoma in the antrum of the stomach: a case report.

Although heterotopic pancreas usually occurs in the stomach and rarely presents as a submucosal tumor, an accurate preoperative diagnosis is often difficult because of the variety of clinical symptoms and findings depending on the size and location of the lesion. We experienced a case of gastric type III heterotopic pancreas presenting as a gastric adenomyoma in the antrum of the stomach. A 62-year-old woman visited a local hospital for epigastric discomfort. An esophagogastroduodenoscopy study indicated a submucosal tumor in the greater curvature of the gastric antrum. The patient underwent surgical resection of the tumor because it was enlarged. The histological sections of the resected specimen showed that the tumor was composed of ductular structures lined by tall columnar epithelia and a prominent smooth muscle stroma with no atypical cells. The tumor was compatible with Heinrich's type III heterotopic pancreas, which presented as an adenomyoma of the stomach. These findings provide useful histological features and some insight into a better understanding of the embryonic origin and development of adenomyoma and heterotopic pancreas in the antrum of the stomach.

Gastric collision tumor composed of early-stage gastric carcinoma and gastrointestinal stromal tumor: a case report.

Collision tumors composed of adenocarcinoma and gastrointestinal stromal tumor (GIST) of the stomach are extremely uncommon, and only a few cases have been reported in the English literature. In the present case, a 67-year-old woman visited a local hospital for vomiting and hematemesis. An esophagogastroduodenoscopy study indicated an elevated lesion with ulceration. Histology of the endoscopic biopsy specimen indicated gastric adenocarcinoma. The patient underwent laparoscopic distal gastrectomy with D2 lymph node dissection. The resected specimen showed that the primary tumor consisted of a GIST and that early-stage gastric carcinoma coexisted in the mucosa surrounding the central ulceration of the GIST. Although close contact of the adenocarcinoma and GIST was observed on the mucosal surface, no intermixing of tumor cells was observed in the primary tumor. This case is an extremely rare case of a collision tumor composed of early-stage gastric adenocarcinoma and GIST occurring in the stomach, which provides some insight into a better understanding of the pathogenesis of collision tumors.

A case of gastric ischemia caused by massive gastric dilatation due to superior mesenteric artery syndrome.

Gastric ischemia is extremely rare and its endoscopic findings appear similar to those of malignant tumors, which makes accurate diagnosis difficult. We present the case of a 41-year-old woman who was admitted to our hospital for severe abdominal pain and vomiting. Laboratory data at the time of admission indicated high serum levels of C-reactive protein, fibrin/fibrinogen degradation products and D-dimer. An abdominal computed tomography (CT) scan revealed a massive dilatation of the stomach and descending portion of the duodenum, which abruptly narrowed at the portion between the superior mesenteric artery and the aorta, indicating massive gastric and duodenal dilatation due to superior mesenteric artery syndrome. Decompression of the upper gastrointestinal tract using a nasogastric tube was started immediately. An esophagogastroduodenoscopy revealed a massive, irregular ulcerative lesion with ill-defined boundaries located in the posterior wall along the greater curvature of the stomach. Although this lesion mimicked a malignant lesion, the biopsy findings revealed a benign gastric ulcer, indicating that the lesion was gastric ischemia caused by the increased intragastric pressure resulting from the massive dilatation. The gastric ischemia healing process was successfully observed through repeated endoscopic examinations of the upper gastrointestinal tract. The patient's abdominal symptoms disappeared within 10 days and she was discharged from the hospital 23 days after the abdominal episode. This case highlights gastric ischemia associated with an acute massive gastric dilatation resulting in increased intragastric pressure caused by superior mesenteric artery syndrome.

Bence-Jones protein-type myeloma with amyloid myopathy presenting as amyloidomas and extensive amyloid deposits in the muscularis propria: a rapidly fatal autopsy case.

This study reports a 59-year-old man who suffered from multiple skeletal muscle amyloidomas and showed a rapidly fatal course. He noticed left inguinal pain and gait disturbance due to muscle weakness of the left leg. Protein in urine (3.3 g/d) and Bence-Jones protein of the κ type (2.3 g/d) were detected. Bone marrow aspiration showed 11.6% monoclonal plasma cells in nucleated cells. A core needle-biopsied and resected left inguinal tumor showed the deposition of eosinophilic amorphous materials positive for Congo red stain and the κ-light chain. He was diagnosed with plasma cell myeloma with AL (amyloid light chain) amyloidosis. Multiple soft-part tumors developed, grew rapidly, and he died 3 months after admission. At autopsy, 3 large amyloidomas were observed in the skeletal muscles, and prominent amyloid deposits were also seen in the diaphragm, intercostal muscle, iliopsoas muscle, and cervical skeletal muscles examined. Massive amyloid materials deposited diffusely in the propria muscularis of the gastrointestinal tract: the tongue to the rectum.

Aggressive carcinoid tumors arising in the duodenum, ileum, and rectum with liver metastasis: a report of three cases.

Three aggressive carcinoid tumors with liver metastasis arising in the duodenum (Case 1, 72-year-old man), ileum (Case 2, 72-year-old man), and rectum (Case 3, 67-year-old woman) were studied. Case 1 initially suffered from hemorrhage from an exophytic large tumor and developed a liver metastasis after operation. Cases 2 and 3 first presented as multiple liver metastases. Case 3 had a small submucosal tumor and showed a relatively high cell proliferation activity. Neoplastic cells expressed gastrin in Case 1, serotonin in Case 2, and did not express several peptides in Case 3.

Mitochondrial signal lacking manganese superoxide dismutase failed to prevent cell death by reoxygenation following hypoxia in a human pancreatic cancer cell line, KP4.

One of the major characteristics of tumor is the presence of a hypoxic cell population, which is caused by abnormal distribution of blood vessels. Manganese superoxide dismutase (MnSOD) is a nuclear-encoded mitochondrial enzyme, which scavenges superoxide generated from the electron-transport chain in mitochondria. We examined whether MnSOD protects against hypoxia/reoxygenation (H/R)-induced oxidative stress using a human pancreas carcinoma-originated cell line, KP4. We also examined whether MnSOD is necessarily present in mitochondria to have a function. Normal human MnSOD and MnSOD without a mitochondrial targeting signal were transfected to KP4 cells, and reactive oxygen species, nitric oxide, lipid peroxidation, and apoptosis were examined as a function of time in air following 1 day of hypoxia as a H/R model. Our results showed H/R caused no increase in nitric oxide, but resulted in increases in reactive oxygen species, 4-hydroxy-2-nonenal protein adducts, and apoptosis. Authentic MnSOD protected against these processes and cell death, but MnSOD lacking a mitochondrial targeting signal could not. These results suggest that only when MnSOD is located in mitochondria is it efficient in protecting against cellular injuries by H/R, and they also indicate that mitochondria are primary sites of H/R-induced cellular oxidative injuries.