Abstract
Background: A majority of gastrointestinal tumors are adenocarcinoma. Rarely, there is also a type of tumors such as acinar cell carcinoma, which are often called pancreatic-type acinar cell carcinoma. Among those, some are differentiated into neuroendocrine components. A few of them can be called MiNENs. Case presentation: The patient was an 80-year old male who was referred to our hospital for treatments of a pedunculated gastric tumor. It was 5 cm in diameter and detected in the upper gastric body with upper GI endoscopy conducted for investigation of anemia. In the biopsy, although a kind of hyperplasia of gastric gland cell was pointed out, no tumor cells were found. Retrospectively, the diagnosis was turned out to be a misdiagnosis. An operation was arranged because bleeding from the tumor was suspected as a cause of anemia and because a surgical resection was considered to be desirable for accurate diagnosis. Hence, laparoscopy and endoscopy cooperative surgery was performed. In pathological examination, several types of epithelial cells which proliferated in the area between mucosa and deep inside the submucosa were observed. These consisted of acinar-glandular/trabecular patterns and solid pattern. A diagnosis of pancreatic-type acinar cell carcinoma of the stomach with NET G2 and G3 was made based on characteristic cellular findings and the result of immunostaining tests. Each of them consisted of more than 30% of the lesion; a diagnosis of pancreatic-type mixed acinar neuroendocrine carcinoma (pancreatic-type MiNEN) of the stomach, or a type of gastric MiNEN was obtained. Anemia was resolved after operation, and the patient was discharged from the hospital without perioperative complications. Conclusions: Pancreatic-type ACC of the stomach which is differentiated into neuroendocrine tumor is very rare. Hence, we report this case along with several literature reviews.
Case report: Novel PIK3CA and AXIN1 mutations in acinar cell carcinoma of the stomach arising from pancreatic heterotopia
