A mutation spectrum that includes GNAS, KRAS and TP53 may be shared by mucinous neoplasms of the appendix

摘要: Appendiceal mucinous tumors (AMTs) are classified as low-grade appendiceal neoplasms (LAMNs) or adenocarcinomas (MACs), although their carcinogenesis is not well understood. As somatic activating mutations of GNAS considered to be characteristic LAMNs while TP53 have been shown specific MACs, MACs unlikely result from transformation LAMNs. However, emerging evidence also shows the presence in MACs. We examined 16 AMTs (11 and 5 MACs) for genetic alterations GNAS, KRAS, BRAF, TP53, CTNNB1, TERT promoter order elucidate possibility a shared background two tumor types. Extensive histological examination revealed component all cases MAC. were detected one MAC, mutation this MAC was nonsense (Q227X) expected mutation. three LAMNs; they frequently KRAS CTNNB1 occurred exclusively AMTs. BRAF detected. Overexpression p53 observed only immunostaining clearly discriminated high-grade lesion one. These findings suggest that overexpression plays an important role that, addition might by AMTs, thus providing possible progression