Department of Pathology, Molecular and Cell Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Mod Pathol. 2022 Nov;35(11):1732-1739. doi: 10.1038/s41379-022-01114-7. Epub 2022 Jun 8.
Appendiceal mucinous neoplasms (AMNs), characterized by expansile or "pushing" growth of neoplastic epithelium through the appendix wall, are sometimes accompanied by peritoneal involvement, the extent and grade of which largely determine clinical presentation and long-term outcomes. However, the prognosis of tumors entirely confined to the appendix is still debated and confusion remains regarding their biologic behavior and, consequently, their clinical management and even diagnostic nomenclature. We evaluated AMNs limited to the appendix from 337 patients (median age: 58 years, interquartile range (IQR): 47-67), 194 (57.6%) of whom were women and 143 (42.4%) men. The most common clinical indication for surgery was mass or mucocele, in 163 (48.4%) cases. Most cases (N = 322, 95.5%) comprised low-grade epithelium, but there were also 15 (4.5%) cases with high-grade dysplasia. Lymph nodes had been harvested in 102 (30.3%) cases with a median 6.5 lymph nodes (IQR: 2-14) per specimen for a total of 910 lymph nodes examined, all of which were negative for metastatic disease. Histologic slide review in 279 cases revealed 77 (27.6%) tumors extending to the mucosa, 101 (36.2%) to submucosa, 33 (11.8%) to muscularis propria, and 68 (24.4%) to subserosal tissues. In multivariate analysis, deeper tumor extension was associated with older age (p = 0.032; odds ratio (OR): 1.02, 95% confidence intervals (CI): 1.00-1.03), indication of mass/mucocele (p < 0.001; OR: 2.09, CI: 1.41-3.11), and wider appendiceal diameter, grossly (p < 0.001; OR: 1.61, CI: 1.28-2.02). Importantly, among 194 cases with at least 6 months of follow-up (median: 56.1 months, IQR: 24.4-98.5), including 9 high-grade, there was no disease recurrence/progression, peritoneal involvement (pseudomyxoma peritonei), or disease-specific mortality. These data reinforce the conclusion that AMNs confined to the appendix are characterized by benign biologic behavior and excellent clinical prognosis and accordingly suggest that revisions to their nomenclature and staging would be appropriate, including reverting to the diagnostic term mucinous adenoma in order to accurately describe a subset of them.
阑尾黏液性肿瘤（AMN）的特点是肿瘤上皮通过阑尾壁呈膨胀性或“推进性”生长，有时伴有腹膜受累，腹膜受累的程度和分级在很大程度上决定了临床表现和长期预后。然而，完全局限于阑尾的肿瘤的预后仍存在争议，并且其生物学行为仍然存在混淆，因此其临床管理甚至诊断命名法也存在混淆。我们评估了来自 337 名患者（中位年龄：58 岁，四分位距（IQR）：47-67）的局限于阑尾的 AMN，其中 194 名（57.6%）为女性，143 名（42.4%）为男性。手术最常见的临床指征是肿块或黏液囊肿，占 163 例（48.4%）。大多数病例（N=322，95.5%）为低级别上皮，但也有 15 例（4.5%）为高级别异型增生。102 例（30.3%）患者进行了淋巴结采集，每例标本的中位数为 6.5 个淋巴结（IQR：2-14），共检查了 910 个淋巴结，均未发现转移性疾病。在 279 例病例的组织学切片复查中，77 例（27.6%）肿瘤延伸至黏膜，101 例（36.2%）延伸至黏膜下层，33 例（11.8%）延伸至固有肌层，68 例（24.4%）延伸至浆膜下层。多变量分析显示，肿瘤的更深层延伸与年龄较大（p=0.032；优势比（OR）：1.02，95%置信区间（CI）：1.00-1.03）、肿块/黏液囊肿的指征（p<0.001；OR：2.09，CI：1.41-3.11）和更大的阑尾直径（p<0.001；OR：1.61，CI：1.28-2.02）有关。重要的是，在 194 例至少有 6 个月随访的病例中（中位随访时间：56.1 个月，IQR：24.4-98.5），包括 9 例高级别病例，均无疾病复发/进展、腹膜受累（假性黏液瘤）或疾病特异性死亡。这些数据进一步证实了这样的结论，即完全局限于阑尾的 AMN 具有良性的生物学行为和良好的临床预后，因此建议对其命名法和分期进行修订，包括恢复使用诊断术语“黏液性腺瘤”，以便更准确地描述其中的一部分。
