Guo Zhitang, Long Kui, Chen Zhanbin, Zhang Wei, Chu Quanxian
Department of Hepatopancreatobiliary Surgery, The Second Affiliated Hospital of Kunming Medical University, Kunming, China.
Department of General Surgery, Nujiang Prefecture People's Hospital, Nujiang, Yunnan, China.
Medicine (Baltimore). 2024 Dec 13;103(50):e40911. doi: 10.1097/MD.0000000000040911.
Low-grade appendiceal mucinous neoplasm (LAMN) is a clinically rare tumor that predominantly occurs in females and presents with nonspecific symptoms, often resulting in misdiagnosis. While postoperative pathology remains the gold standard for diagnosis, accurate preoperative identification through various diagnostic methods is essential for effective treatment planning. To raise awareness of this condition, we present a case of a middle-aged male diagnosed with LAMN.
A 52-year-old male presented to outpatient clinic with right lower abdominal pain lasting 1 day. He described the pain as continuous cramping, exacerbated by movement and coughing, with associated nausea.
Physical examination revealed tenderness in the right lower quadrant and a palpable mass measuring approximately 6.5 cm × 5.0 cm, with poor definition and limited mobility. An elevated white blood cell count (16.2 × 109/L) and a mixed cystic and solid mass were noted, prompting admission for further evaluation. Further, abdominal enhanced computed tomography revealed a mixed-density lesion in the right ileocecal region, measuring approximately 6.5 cm × 5.0 cm. This finding was suggestive of an appendiceal mucinous neoplasm, with mucinous adenocarcinoma remaining a possibility that could not be excluded.
The patient underwent a laparoscopic right hemicolectomy on June 5, 2024, and the gross specimen showed: a 6.5 cm × 5.0 cm mass was found in the appendix area on the surface of the intestinal tube, a large amount of jelly was found after incision, and the mass was connected to the intestinal cavity.
The patient recovered well after surgery, the abdominal drainage tube was pulled out on the 8th day after surgery, and the patient was discharged on the 13th day after surgery. Postoperative examination showed LAMN and mucus accumulation in the wall of the appendix with a foreign body giant cell reaction, acute attack of chronic appendicitis, and suppurative inflammation with peripheral inflammation. Postoperative diagnosis: LAMN; acute chronic appendicitis attack.
As a rare clinical gastrointestinal tumor, LAMN lacks specific clinical manifestations, and its diagnosis depends on postoperative examination; however, the indications for surgery are clear and the clinical prognosis is good. The key to surgery is to protect the tumor body to avoid rupture and cause the development of peritoneal pseudomyxoma (PMP).
低度阑尾黏液性肿瘤（LAMN）是一种临床罕见的肿瘤，主要发生于女性，症状不具特异性，常导致误诊。虽然术后病理仍是诊断的金标准，但通过各种诊断方法进行准确的术前识别对于有效的治疗规划至关重要。为提高对该病的认识，我们报告一例诊断为LAMN的中年男性病例。
一名52岁男性因右下腹痛1天前来门诊就诊。他描述疼痛为持续性绞痛，活动和咳嗽时加重，伴有恶心。
体格检查发现右下腹压痛，可触及一个约6.5 cm×5.0 cm的肿块，边界不清，活动度有限。白细胞计数升高（16.2×10⁹/L），并发现一个混合性囊实性肿块，遂收治入院进一步评估。此外，腹部增强计算机断层扫描显示右回盲部有一个混合密度病变，大小约为6.5 cm×5.0 cm。这一发现提示为阑尾黏液性肿瘤，黏液腺癌仍有可能，不能排除。
患者于2024年6月5日接受了腹腔镜右半结肠切除术，大体标本显示：在肠管表面阑尾区域发现一个6.5 cm×5.0 cm的肿块，切开后发现大量胶冻样物，肿块与肠腔相连。
患者术后恢复良好，术后第8天拔除腹腔引流管，术后第13天出院。术后检查显示为LAMN，阑尾壁有黏液积聚并伴有异物巨细胞反应、慢性阑尾炎急性发作及周围化脓性炎症。术后诊断：LAMN；急性慢性阑尾炎发作。
作为一种罕见的临床胃肠道肿瘤，LAMN缺乏特异性临床表现，其诊断依赖于术后检查；然而，手术指征明确，临床预后良好。手术的关键是保护肿瘤体，避免破裂导致腹膜假黏液瘤（PMP）的发生。
