Gastric Collision Tumor (Adenocarcinoma and Neuroendocrine carcinoma) Diagnosed as a Advanced Gastric Cancer

The collision tumors have been reported in various organs and represent the coexistence of two adjacent but histologically distinct tumors in an organ without any histological admixture. A gastric collision tumor is rare and most gastric collision tumors involve an adenocarcinoma colliding with a lymphoma. A 48-year-old man was referred to our hospital for an evaluation of dyspepsia and upper abdominal discomfort. Endoscopy demonstrated the presence of an ulcerative lesion in the gastric antrum. The biopsy specimens confirmed a pathological diagnosis of an adenocarcinoma. After a radical subtotal gastrectomy, a thorough Histopathological examination revealed a collision tumor: a well-differentiated adenocarcinoma in the superficial layer (mucosa, submucosa) and a poorly differentiated neuroendocrine carcinoma in the deeper layer (muscularis propria, serosa). The patient received combination chemotherapy with cisplatin and etoposide. Para-aortic lymph node enlargement was observed on the abdominal computed tomography scanning, 3 years after surgery. The patient underwent chemotherapy with TS-1, and the size of lymph nodes was reduced. The patient continues to do well after a follow up period of 5 years 3 months. We report this case of gastric collision tumor (adenocarcinoma and neuroendocrine carcinoma) with a brief review of the relevant literature.

RImmunohistochemical Evaluation of E-cadherin/catenin (alpha-, beta-, gamma-catenin and p120CTN) Complex Expression in Early Gastric Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The significance of abnormal E-cadherin/ catenin complex expression and the correlation of each of its components in cancer remain unclear. This study aimed to characterize the clinical significance of the abnormal membrane expression of the E-cadherin/ catenin complex and the localization patterns of the beta- catenin and p120CTN in early gastric cancer. MATERIALS AND METHODS: Immunohistochemical staining for E-cadherin, alpha-, beta- and gamma-catenin and p120CTN were performed on 47 early gastric cancer specimens. The patterns of membrange expression of the E-cadherin/catenin complex, and the localization patterns of the beta-catenin and p120CTN, were semi quantitatively graded as loss, reduced, preserved or negative and positive. RESULTS: An abnormal immunoreactivity of at least one of E-cadherin/catenin complex proteins was noted in 46 (97.8%) of the 47 early gastric cancer cases. There were no significant correlations of the membrane E-cadherin/catenin expression with, either, sex, age, location, size, macroscopic type, depth of invasion or lymphovascular invasion. Abnormal expressions of membrane E-cadherin, beta-catenin and gamma-catenin were more frequent in the diffuse-type than in the intestinal type. No linear correlation was shown for the beta-catenin between the membrane and cytoplasmic expressions. Nuclear staining of the beta-catenin was observed in 5 (10.6%) cases, but nuclear staining of the p120CTN, a promotor of Kaiso transcriptional factor, was not seen. CONCLUSION: These results suggest that alterations of the E-cadherin/catenin complex may be involved in the early stages of gastric cancer. Although beta-catenin functions as a transcriptional factor, the inactivation of membrane E-cadherin does not appear to result in significant increases in the level of cytoplasmic beta-catenin. Kaiso transcriptional factor may not be involved in the early carcinogenesis of gastric cancer.