UNASSIGNED: Appendiceal @entity5 (AMTs) are classified as low-grade appendiceal @entity5 (LAMNs) or @entity3079 ( @entity3079 ), although their carcinogenesis is not well understood. As somatic activating mutations of @entity2163 are considered to be characteristic of LAMNs while @entity876 mutations have been shown to be specific to @entity3079 , @entity3079 are unlikely to result from transformation of LAMNs. However, emerging evidence also shows the presence of @entity2163 mutations in @entity3079 . We examined 16 AMTs (11 LAMNs and 5 @entity3079 ) for genetic alterations of @entity2163 , @entity984 , @entity817 , @entity876 , @entity3546 , and @entity2215 promoter in order to elucidate the possibility of a shared genetic background in the two @entity5 types. Extensive histological examination revealed the presence of a low-grade component in all cases of MAC. @entity2163 mutations were detected in two LAMNs and in one MAC, although the @entity2163 mutation in this MAC was a nonsense mutation ( @entity69722 ) expected not to be activating mutation. @entity876 mutations were detected in three LAMNs; they were frequently detected in @entity3079 . @entity984 mutations were detected in three LAMNs and three @entity3079 , and @entity3546 mutations were detected in two LAMNs. @entity984 mutation and activating mutation of @entity2163 occurred exclusively in AMTs. @entity817 and @entity2215 mutations were not detected. Overexpression of @entity876 was observed in only two @entity3079 , and @entity876 immunostaining clearly discriminated the high-grade lesion from a low-grade component in one. These findings suggest that @entity876 overexpression plays an important role in the carcinogenesis of AMTs and that, in addition to mutations of @entity2163 , @entity984 and @entity876 alterations might be shared by AMTs, thus providing evidence for the possible progression of LAMNs to MAC.

A mutation spectrum that includes @entity2163 , @entity984 and @entity876 may be shared by XXXX of the appendix.

@entity2163 :: ('2778', 'Gene') :: ['GNAS'] @entity3079 :: ('MESH:D002288', 'Disease') :: ['MACs', 'mucinous adenocarcinomas'] @entity5 :: ('MESH:D009369', 'Disease') :: ['mucinous tumors', 'tumor', 'mucinous neoplasms'] @entity984 :: ('3845', 'Gene') :: ['KRAS'] @entity876 :: ('7157', 'Gene') :: ['p53', 'TP53'] @entity3546 :: ('1499', 'Gene') :: ['CTNNB1'] @entity69722 :: ('p|SUB|Q|227|X', 'ProteinMutation') :: ['Q227X'] @entity817 :: ('673', 'Gene') :: ['BRAF'] @entity2215 :: ('7015', 'Gene') :: ['TERT']
@entity5 :: (MESH:D009369,Disease) :: ['mucinous neoplasms']
