[Clinicopathological analysis and surgical strategy of primary appendiceal neoplasms].

Objective: To investigate the clinicopathological features, surgical methods and prognosis of primary appendiceal neoplasms. Methods: A descriptive case series study was performed. Clinical data of patients diagnosed with primary appendiceal neoplasms in Peking University First Hospital from 2006 to 2017 were retrospectively analyzed. Patients who underwent surgery and were confirmed as appendiceal neoplasms by postoperative pathology were included. Cases of cecal tumor invading the appendix and other organ tumors implanting in the appendix and cases of recurrent appendix tumors were excluded Pathological classification was based on the 4th edition of the WHO classification of digestive tract tumors (2010 edition), and the efficacy of operation methods of low grade appendiceal mucinous neoplasm (LAMN) were analyzed. Results: A total of 115 patients were enrolled, including 52 males and 63 females with a median age of 59 (51, 71) years. Clinical symptoms usually manifested as dormant pain in the right lower quadrant, migrating right lower abdominal pain, fever and bloating. Twenty-four cases were accidentally discovered during surgery, and 21 cases were found by physical examination. The preoperative diagnosis rate of CT and ultrasound was 40.2% (43/107) and 25.5% (24/94) respectively. The postoperative pathological types contained 83 cases of LAMN, 12 cases of mucinous adenocarcinoma, 9 cases of appendiceal neuroendocrine neoplasms (aNEN), 2 cases of mucinous adenocarcinoma with signet ring cells, 3 cases of serrated adenoma, 2 cases of goblet cell carcinoid, 2 cases of lymphoma, 1 case of leiomyoma and 1 case of schwannomas. All the patients underwent surgical resection, including 41 cases of appendectomy, 21 cases of partial cecectomy, 48 cases of right hemicolectomy, and 5 cases of combined organ resection due to appendiceal tumor infiltration or dissemination. Eighteen cases were diagnosed with pseudomyxoma peritonei (PMP) during operation. A total of 98 patients were enrolled for follow-up. The median follow-up time was 58 (5-172) months. The 5-year disease-free survival (DFS) rate was 84.5% and 5-year overall survival (OS) was 88.2%. Multivariate analysis revealed that high-grade malignancy tumors (HR=25.881, 95% CI: 2.827-236.935, P=0.004) and PMP formation (HR=42.166, 95% CI: 3.470-512.439,P=0.003) were independent risk factors for prognosis. Patients undergoing right hemicolectomy presented longer operation time, more blood loss and higher morbidity of complication as compared to those undergoing appendectomy and partial cecectomy (all P<0.05), while no significant differences in 5-year DFS (P=0.627) and 5-year OS (P=0.718) were found. Conclusions: Primary appendiceal neoplasms usually have no typical features, accompanied with low preoperative diagnosis rate. The common pathological types are LAMN, mucinous adenocarcinoma and aNEN. Appendectomy or partial cecectomy for LAMN may achieve satisfactory prognosis. High-grade malignancy tumors and PMP formation are independent risk factors for prognosis.目的： 探讨原发性阑尾肿瘤的临床病理特征、手术方式及预后。 方法： 采用描述性病例系列研究方法，回顾性分析2006—2017年间北京大学第一医院诊断的原发性阑尾肿瘤患者的临床病理资料。采用世界卫生组织消化道肿瘤第四版进行病理分类，着重对低级别阑尾黏液性肿瘤（LAMN）的手术方式进行疗效分析。纳入接受手术并经术后病理证实为阑尾肿瘤的病例。排除盲肠肿瘤侵犯阑尾和其他脏器肿瘤种植于阑尾的病例和复发阑尾肿瘤病例。收集观察临床病理资料、治疗情况、原发性阑尾肿瘤患者的3年、5年的无复发生存率和总体生存率，并分析阑尾切除和盲肠部分切除对比右半结肠切除方式治疗LAMN的疗效。 结果： 共计纳入115例原发性阑尾肿瘤患者，其中男性52例，女性63例，中位年龄59（51，71）岁。临床表现为右下腹固定隐痛、转移性右下腹痛、发热和腹胀。24例由术中偶然发现，21例由体检发现。术前CT和B超确诊率分别为40.2%（43/107）和25.5%（24/94）。术后病理类型包括LAMN 83例、黏液腺癌12例、阑尾神经内分泌肿瘤（aNEN）9例、黏液腺癌伴印戒细胞成分2例、锯齿状腺瘤3例、杯状细胞类癌2例、淋巴瘤2例、平滑肌瘤1例、神经鞘瘤1例。所有患者均接受手术切除，其中阑尾切除术41例，盲肠部分切除术21例，右半结肠切除术48例，因阑尾肿瘤浸润或播散而行联合脏器切除5例。18例患者术中发现腹膜假性黏液瘤（PMP）。共纳入98例原发性阑尾肿瘤患者进行随访。中位随访时间58（5~172）个月，本组原发性阑尾肿瘤患者5年的无复发生存率和总体生存率分别为84.5%和88.2%。多因素分析结果显示，恶性程度高（HR=25.881，95% CI：2.827~236.935，P=0.004）和PMP形成（HR=42.166，95% CI：3.470~512.439，P=0.003）是影响原发性阑尾肿瘤患者预后的独立危险因素。右半结肠切除术组的手术时长、出血量和并发症发生率均高于阑尾或盲肠部分切除组（均P<0.05），但两组5年无复发生存率和5年总体生存率方面差异均无统计学意义（P=0.627，P=0.718）。 结论： 原发性阑尾肿瘤临床症状不典型，术前诊断率低。LAMN、黏液腺癌和aNEN是常见的病理类型。阑尾切除术或盲肠部分切除术治疗LAMN可获得较好的预后。肿瘤恶性程度高和伴发PMP是影响原发性阑尾肿瘤患者预后的独立危险因素。.