Department of Hepato-Biliary-Pancreatic Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan.
Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan.
Clin J Gastroenterol. 2021 Oct;14(5):1364-1370. doi: 10.1007/s12328-021-01452-0. Epub 2021 May 30.
A paraganglioma is a tumor originating in the sympathetic or parasympathetic nervous system. Its diagnosis may sometimes be confusing if it occurs in an atypical site. We described herein a case of a peripancreatic paraganglioma originating in the greater omentum. An asymptomatic, 61-year-old, female patient was referred to our hospital for detailed examination of a peripancreatic mass detected incidentally on computed tomography (CT). The differential diagnosis was a neuroendocrine neoplasm (NEN), and a biopsy using EUS-FNA was performed. Histologically, the tumor cells showed proliferation in solid cell nests and were positive for CD56, chromogranin A, and synaptophysin. These findings and the hypervascularity of the tumor on imaging studies were compatible with NEN. Since the imaging studies did not clearly demonstrate the continuity of the tumor with the pancreas, laparoscopic tumor resection without a pancreatectomy and sampling of the enlarged peripancreatic lymph nodes were planned as treatment. The absence of continuity with the pancreas was later confirmed by intraoperative observation, and the resection was carried out as planned. The resected tumor was pathologically considered as NEN at first in agreement with the preoperative diagnosis. However, several histological findings (such as a zelleballen-like growth pattern, pseudo-inclusion, and strong nuclear atypia compared with the cells' proliferative ability) were atypical for NEN, and paraganglioma was included in the differential diagnosis. Additional immunostainings of S-100 and AE1/AE3 were performed, leading to the final diagnosis of paraganglioma. Paragangliomas should be included in the differential diagnosis of an intraperitoneal mass of uncertain identity with hypervascularity.
副神经节瘤起源于交感或副交感神经系统。如果发生在非典型部位，其诊断有时可能会令人困惑。我们在此描述了一例发生在大网膜的胰周副神经节瘤。一位 61 岁无症状女性患者因偶然在计算机断层扫描 (CT) 上发现胰周肿块而被转诊至我院进行详细检查。鉴别诊断为神经内分泌肿瘤 (NEN)，并进行了 EUS-FNA 活检。组织学上，肿瘤细胞呈实性巢状增殖，CD56、嗜铬粒蛋白 A 和突触素阳性。这些发现以及肿瘤在影像学研究中的富血管性与 NEN 相符。由于影像学研究未能明确显示肿瘤与胰腺的连续性，因此计划进行腹腔镜肿瘤切除而不进行胰切除术，并对增大的胰周淋巴结进行取样。术中观察证实了与胰腺无连续性，随后按计划进行了切除。切除的肿瘤最初在病理上被认为是 NEN，与术前诊断相符。然而，一些组织学发现（如 zelleballen 样生长模式、假包涵体和与细胞增殖能力相比核异型性较强）与 NEN 不符，因此纳入了副神经节瘤的鉴别诊断。进一步进行了 S-100 和 AE1/AE3 的免疫组化染色，最终诊断为副神经节瘤。副神经节瘤应纳入具有富血管性的腹腔内性质不明肿块的鉴别诊断中。
