Background: Despite predominant microsatellite instability (MSI) in intestinal-type gastric carcinomas, we found the most frequent MSI in solid-type poorly differentiated adenocarcinoma (PDA). Although this tumor is classified as PDA, it is hypothesized to possess peculiar features among PDAs VSports手机版. The present study aimed to clarify the clinicopathological and molecular characteristics of this tumor. .

Methods: We examined the expression of p53, mismatch-repair proteins, and mucin core glycoproteins; microsatellite status; and mutations in KRAS and BRAF, as well as clinicopathological features, in 54 cases of PDA of the stomach (31 solid-type PDAs and 23 non-solid-type PDAs). V体育安卓版.

Results: The proportion (51. 6%) of MSI in solid-type PDA was significantly higher than that in non-solid-type PDA (4. 5%) (p = 0. 00022). The proportion of absent expression of MLH1 (58. 1%) and PMS2 (51. 6%) in solid-type PDA was significantly higher than that in non-solid-type PDA (4. 5 and 8%) (p < 0. 0001). No differences were found in the mutations of KRAS and BRAF among PDAs V体育ios版. MSI-positive solid-type PDA was significantly associated with older age, female predominance, lower third location, concordant glandular component, and absent MLH1 and PMS2 expression. .

Conclusions: These results suggest that MSI-positive solid-type PDA has peculiar clinicopathological features and that MSI with absent MLH1 and PMS2 expression may play an important role in tumor development. In addition, from the viewpoint of histogenesis, MSI-positive solid-type PDA may originate from differentiated-type adenocarcinoma. VSports最新版本.