Dartigues Peggy, Kepenekian Vahan, Illac-Vauquelin Claire, Verriele Véronique, Fontaine Juliette, Isaac Sylvie, Chevallier Anne, Valmary-Degano Séverine, Laverriere Marie-Hélène, Avérous Gerlinde, Bibeau Frédéric, Villeneuve Laurent, Glehen Olivier, Benzerdjeb Nazim
Department of Pathology, Gustave Roussy Institute, Villejuif.
CICLY-EA3738, University Claude Bernard Lyon I (UCBL1).
Am J Surg Pathol. 2025 May 1;49(5):499-507. doi: 10.1097/PAS.0000000000002373. Epub 2025 Feb 20.
High-grade appendiceal mucinous neoplasm (HAMN) is used to describe a rare epithelial neoplasm of the appendix characterized by pushing-type invasion and high-grade cytologic atypia. Its implications regarding lymph node spread and the necessity of right colectomy are currently debate. The objective of the present study was to assess the clinicopathologic characteristics, the risk of lymph node and peritoneal metastasis, and long-term outcomes of patients diagnosed as HAMN in comparison to low-grade appendiceal mucinous neoplasm (LAMN) and appendiceal adenocarcinoma, treated by right hemicolectomy. A total of 443 patients diagnosed with LAMN (n=246), HAMN (n=34), or appendiceal adenocarcinoma (n=163) and who underwent right colectomy with lymph node dissection in all cases within 32 institutions of the French Network for Rare Peritoneal Malignancies (RENAPE) were included. The median age was 56.5 years (range: 21 to 91), and the majority were female (n=250, 56.4%) without difference between groups ( P =0.604). Lymph node metastases were identified in 17.8% of appendiceal adenocarcinoma cases (29/163); none were found among LAMN or HAMN cases. A higher number of lymph nodes were analyzed in those treated for appendiceal adenocarcinoma than LAMN ( P <0.001) and HAMN ( P =0.035). Regarding peritoneal metastasis, a higher proportion of cases were classified as high-grade with/without signet cells in patients treated for HAMN ( P <0.001) and appendiceal adenocarcinoma ( P <0.001) than those treated for LAMN. Among patients with perforation of the appendix, those treated for LAMN had longer overall survival (OS; P <0.001) and progression-free survival (PFS; P <0.0001) than those treated for appendiceal adenocarcinoma or those treated for HAMN; among patients without perforation, those treated for LAMN and HAMN had longer OS ( P =0.042) and PFS ( P =0.012) than those treated for appendiceal adenocarcinoma. No lymph node metastases were observed in patients treated for HAMN, and those without appendix perforation had a similar prognosis to LAMN. This study supports staging HAMN using the same system as LAMN and treating it with appendectomy alone in the absence of appendix perforation.
高级别阑尾黏液性肿瘤（HAMN）用于描述一种罕见的阑尾上皮性肿瘤，其特征为推挤式浸润和高级别细胞学异型性。目前，关于其淋巴结转移情况以及右半结肠切除术的必要性仍存在争议。本研究的目的是评估经右半结肠切除术治疗的被诊断为HAMN的患者的临床病理特征、淋巴结及腹膜转移风险和长期预后，并与低级别阑尾黏液性肿瘤（LAMN）及阑尾腺癌进行比较。法国罕见腹膜恶性肿瘤网络（RENAPE）的32家机构共纳入了443例被诊断为LAMN（n = 246）、HAMN（n = 34）或阑尾腺癌（n = 163）且均接受了淋巴结清扫的右半结肠切除术的患者。中位年龄为56.5岁（范围：21至91岁），大多数为女性（n = 250，56.4%），各组间无差异（P = 0.604）。在阑尾腺癌病例中，17.8%（29/163）发现有淋巴结转移；LAMN或HAMN病例中均未发现。接受阑尾腺癌治疗的患者分析的淋巴结数量多于LAMN（P < 0.001）和HAMN（P = 0.035）。关于腹膜转移，与接受LAMN治疗的患者相比，接受HAMN（P < 0.001）和阑尾腺癌治疗（P < 0.001）的患者中，有/无印戒细胞的高级别病例比例更高。在阑尾穿孔的患者中，接受LAMN治疗的患者的总生存期（OS；P < 0.001）和无进展生存期（PFS；P < 0.0001）长于接受阑尾腺癌或HAMN治疗的患者；在无穿孔的患者中，接受LAMN和HAMN治疗的患者的OS（P = 0.042）和PFS（P = 0.012）长于接受阑尾腺癌治疗的患者。接受HAMN治疗的患者未观察到淋巴结转移，且无阑尾穿孔的患者预后与LAMN相似。本研究支持采用与LAMN相同的系统对HAMN进行分期，且在无阑尾穿孔的情况下仅行阑尾切除术治疗。
