Nakaguro M, Urano M, Ogawa I, et al. - Researchers examined the histologic characteristics of minor salivary gland tumors exhibiting a predominant papillary-cystic structure. In addition, they determined further mutational aspects with a particular focus on sialadenoma papilliferum (SP) and intraductal papillary mucinous neoplasm (IPMN). Among the 28 retrieved papillary-cystic tumors of the minor salivary glands, following histologic classifications were done: SP (n = 10), SP-like intraductal papillary tumor (SP-IPT) (n = 2), IPMN (n = 9), intraductal papilloma, cystadenoma, and cystadenocarcinoma (2-3 cases each). While SP typically presented with a combination of exophytic squamous epithelium and endophytic intraductal papillary infoldings, the exophytic component was lacking in SP-IPT lacked. BRAF V600E mutations were frequently observed in SP and SP-IPT (75.0%); these were identified in both squamous and ductal components. A well-demarcated cystic lesion filled exclusively with a papillary proliferation of mucinous cells and a high rate of AKT1 E17K mutations (88.9%) characterized IPMN. With an intraluminal papillary growth of bland columnar cells, intraductal papillomas were a unilocular cystic lesion. In contrast, a multicystic appearance with papillary configuration was observed in both cystadenomas and cystadenocarcinomas. The surrounding tissue invasion and markedly atypical tumor cell composition were observed in cystadenocarcinomas. Hence for the correct diagnosis of minor salivary gland papillary-cystic tumors, appropriate interpretation of histologic findings and specific genetic alterations (eg, BRAF V600E and AKT1 E17K in SP and IPMN) are essential.