分化良好的乳头状腹膜间皮瘤 (WDPMT) 尚未得到充分研究，并且与腹膜间皮瘤 (PM) 不同。我们报告了大型前瞻性 WDPMT 队列的临床病理特征和结果。对 2007 年 8 月至 2020 年 12 月期间发现的 WDPMT 患者进行随访至 2023 年 1 月。对临床特征和结果进行了注释。根据病理诊断评估总生存期（OS）。分析了种系变异，并将靶向下一代测序 (NGS；MSK-IMPACT) 数据与 PM 和弥漫性胸膜间皮瘤 (DPM) 进行比较。在 54 名患者中，诊断时的中位年龄为 55 岁（范围 20-76 岁），50%为女性 (n = 27)，46% 为吸烟者 (n = 25；中位数 8 包/年)。大多数（94%，n = 51）WDPMT 是在其他适应症（主要是其他恶性肿瘤）的手术探查过程中发现的。两名患者因 WDPMT 接受手术切除；没有人接受 WDPMT 全身治疗。未达到中位 OS（19/54；中位随访时间 4.5 年）。 35% (19/54) 的患者可进行体细胞 NGS。与 PM (0%; 0/50; p < 0.0001) 和 DPM (0%; 0/74; p < 0.0001) 相比，TRAF7 改变在 WDPMT (89%; 17/19) 中丰富。与 PM 和 DPM 相比，WDPMT 中的 BAP1 较少（0% [0/0] vs. 4% [8/50] vs. 46% [34/74]；分别为 p = 0.001 和 p < 0.0001） NF2（0% [0/0] vs. 24% [12/50] vs. 31% [23/74]；分别为 p = 0.03 和 p = 0.001）改变。 23% (4/17) 的 WDPMT 中存在致病性种系变异。分化良好的乳头状腹膜间皮肿瘤主要是偶然发现的。没有与 WDPMT 相关的死亡率，因此常规细胞减灭术或全身治疗没有明显作用。基因组图谱有助于区分 WDPMT 与 DPM 和 PM。© 2024。作者。

Well-differentiated papillary peritoneal mesothelial tumors (WDPMTs) are understudied and discrete from peritoneal mesotheliomas (PMs). We report clinicopathologic characteristics and outcomes of a large prospective WDPMT cohort.Patients with WDPMT identified between August 2007 and December 2020 were followed through January 2023. Clinical characteristics and outcomes were annotated. Overall survival (OS) was assessed from pathologic diagnosis. Germline variants were analyzed, and targeted next-generation sequencing (NGS; MSK-IMPACT) data were compared to PMs and diffuse pleural mesotheliomas (DPMs).Among 54 patients, median age at diagnosis was 55 (range 20-76), 50% were female (n = 27), and 46% were smokers (n = 25; median 8 pack/years). Most (94%, n = 51) WDPMTs were found during surgical explorations for other indications, primarily other malignancies. Two patients underwent surgical resection for WDPMT; none received systemic therapy for WDPMT. Median OS was not reached (19/54; median follow up 4.5 years). Somatic NGS was available for 35% (19/54) of patients. TRAF7 alterations were enriched in WDPMT (89%; 17/19) compared with PM (0%; 0/50; p < 0.0001) and DPM (0%; 0/74; p < 0.0001). In WDPMT compared with PM and DPM, there were less BAP1 (0% [0/0] vs. 4% [8/50] vs. 46% [34/74]; p = 0.001 and p < 0.0001, respectively) and NF2 (0% [0/0] vs. 24% [12/50] vs. 31% [23/74]; p = 0.03 and p = 0.001 respectively) alterations. Pathogenic germline variants were present in 23% (4/17) of WDPMTs.Well-differentiated papillary peritoneal mesothelial tumors were primarily incidental findings. There was no WDPMT-related mortality, so there was no distinct role for routine cytoreductive surgery or systemic therapy. Genomic profiles can help to differentiate WDPMT from DPM and PM.© 2024. The Author(s).