Department of Colorectal Surgery, Changhai Hospital, 168 Changhai Road, Shanghai, 200433, China.
Hereditary Colorectal Cancer Center and Genetic Block Center of Familial Cancer, Changhai Hospital, Shanghai, China.
BMC Gastroenterol. 2020 Jun 1;20(1):167. doi: 10.1186/s12876-020-01238-7.
Juvenile polyposis syndrome (JPS) is a rare disorder characterized by the presence of multiple juvenile polyps in the gastrointestinal tract, and germline mutations in SMAD4 or BMPR1A. Due to its rarity and complex clinical manifestation, misdiagnosis often occurs in clinical practice.
A 42-year-old man with multiple pedunculated colorectal polyps and concomitant rectal adenocarcinoma was admitted to our hospital. His mother had died of colon cancer. He was diagnosed with familial adenomatous polyposis (FAP) and underwent total proctocolectomy and ileal pouch anal anastomosis. Two polyps were selected for pathological examination. One polyp had cystically dilated glands with slight dysplasia. The other polyp displayed severe dysplasia and was diagnosed as adenoma. Three years later, his 21-year-old son underwent a colonoscopy that revealed more than 50 pedunculated colorectal juvenile polyps. Both patients harbored a germline pathogenic mutation in BMPR1A. Endoscopic resection of all polyps was attempted but failed. Finally, the son received endoscopic resection of polyps in the rectum and sigmoid colon, and laparoscopic subtotal colectomy. Ten polyps were selected for pathological examination. All were revealed to be typical juvenile polyps, with cystically dilated glands filled with mucus. Thus, the diagnosis of JPS was confirmed in the son. A review of the literatures revealed that patients with JPS can sometimes have adenomatous change. Most polyps in patients with JPS are benign hamartomatous polyps with no dysplasia. A review of 767 colorectal JPS polyps demonstrated that 8.5% of the polyps contained mild to moderate dysplasia, and only 0.3% had severe dysplasia or cancer. It is difficult to differentiate juvenile polyps with dysplasia from adenoma, which could explain why juvenile polyps have been reported to have adenomatous changes in patients with JPS. Therefore, patients with JPS, especially those with concomitant dysplasia and adenocarcinoma, might be easily diagnosed as FAP in clinical practice.
Juvenile polyp with dysplasia is often diagnosed as adenoma, which might lead to the misdiagnosis of JPS as FAP. The differential diagnosis of JPS versus FAP, should be based on comprehensive evaluation of clinical presentation, endoscopic appearance and genetic investigations; not on the presence or absence of adenoma.
幼年性息肉综合征（JPS）是一种罕见疾病，其特征为胃肠道内存在多个幼年性息肉，以及 SMAD4 或 BMPR1A 的种系突变。由于其罕见性和复杂的临床表现，临床实践中常发生误诊。
一名 42 岁男性，因多发性带蒂结直肠息肉和同时性直肠腺癌入院。他的母亲死于结肠癌。他被诊断为家族性腺瘤性息肉病（FAP），并接受了全直肠结肠切除术和回肠袋肛管吻合术。选择了两个息肉进行病理检查。一个息肉的腺体呈囊性扩张，仅有轻度异型增生。另一个息肉显示重度异型增生，被诊断为腺瘤。三年后，他 21 岁的儿子接受了结肠镜检查，发现 50 多个带蒂结直肠幼年性息肉。两名患者均携带 BMPR1A 的种系致病性突变。尝试行所有息肉的内镜下切除术，但均失败。最终，儿子接受了直肠和乙状结肠息肉的内镜下切除术，以及腹腔镜次全结肠切除术。选择了 10 个息肉进行病理检查。均显示为典型的幼年性息肉，腺体呈囊性扩张，充满黏液。因此，儿子被确诊为 JPS。文献复习显示，JPS 患者有时可出现腺瘤样改变。大多数 JPS 患者的息肉为无异型增生的良性错构瘤性息肉。对 767 例结直肠 JPS 息肉的综述显示，8.5%的息肉含有轻度至中度异型增生，仅有 0.3%的息肉有重度异型增生或癌症。区分伴有异型增生的幼年性息肉和腺瘤较为困难，这可以解释为什么 JPS 患者的幼年性息肉曾被报道有腺瘤样改变。因此，JPS 患者，特别是伴有异型增生和腺癌的患者，在临床上可能容易被误诊为 FAP。
伴有异型增生的幼年性息肉常被误诊为腺瘤，可能导致 JPS 被误诊为 FAP。JPS 与 FAP 的鉴别诊断应基于临床表现、内镜表现和基因检查的综合评估；而不是基于有无腺瘤。
