Division of Hepatobiliary and Pancreas Surgery, Department of Surgery, Mayo Clinic, Rochester, MN, United States.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States.
J Gastrointest Surg. 2024 Nov;28(11):1906-1911. doi: 10.1016/j.gassur.2024.08.010. Epub 2024 Aug 29.
Low-grade appendiceal mucinous neoplasms (LAMNs) can progress to pseudomyxoma peritonei (PMP). The incidence and risk factors for recurrence are unclear, and there is a lack of consensus on the need and duration of surveillance imaging.
Patients at the Mayo Clinic in Rochester, Minnesota, with a histologic diagnosis of LAMNs confined to the appendix and limited involvement of the right lower quadrant from 1992 to 2023 were included. Associations between recurrence and risk factors were assessed using Kaplan-Meier curves and Cox proportional hazards regression.
A total of 125 patients with LAMNs underwent abdominal imaging surveillance for a median of 51.2 months (IQR, 26-92). Of note, 5 patients (4%) recurred, all of which were PMP. Overall, the 5- and 10-year cumulative recurrence incidence rates were 3% and 6%, respectively. The median time to recurrence was 24 months (IQR, 23-87). Only LAMNs limited to the right lower quadrant and LAMN tumor size of <2 cm were associated with recurrence (P < .05). The 5- and 10-year cumulative recurrence risks were 12% and 30%, respectively, for the 21 patients with either risk factor. Only 1% of patients without these 2 risk factors developed a recurrence at 10 years.
The overall recurrence risk of LAMN after resection is low. Appendectomy is sufficient for LAMN. Select patients with acellular mucin confined to the right lower quadrant and a tumor size of <2 cm are at higher risk of recurrence. Thus, long-term surveillance is recommended for high-risk individuals. Conversely, LAMNs without risk factors can be safely observed expectantly.
低级别阑尾黏液性肿瘤（LAMN）可进展为腹膜假黏液瘤（PMP）。复发的发生率和危险因素尚不清楚，对于监测成像的必要性和持续时间也缺乏共识。
本研究纳入了 1992 年至 2023 年期间在明尼苏达州罗切斯特市梅奥诊所就诊的组织学诊断为阑尾 LAMN 且局限于阑尾且右下象限受累有限的患者。使用 Kaplan-Meier 曲线和 Cox 比例风险回归评估复发与危险因素之间的关系。
共有 125 例 LAMN 患者接受了中位时间为 51.2 个月（IQR，26-92）的腹部影像学监测。值得注意的是，5 例（4%）患者复发，均为 PMP。总体而言，5 年和 10 年累积复发发生率分别为 3%和 6%。复发的中位时间为 24 个月（IQR，23-87）。仅局限于右下象限的 LAMN 和肿瘤大小<2cm 的 LAMN 与复发相关（P<0.05）。21 例存在任一危险因素的患者 5 年和 10 年累积复发风险分别为 12%和 30%。无这 2 个危险因素的患者 10 年内仅有 1%发生复发。
LAMN 切除后总体复发风险较低。阑尾切除术足以治疗 LAMN。局限于右下象限且无细胞黏液、肿瘤大小<2cm 的患者复发风险较高。因此，建议对高危人群进行长期监测。相反，无危险因素的 LAMN 可以安全地进行观察。
