Division of Gastroenterology, Department of Internal Medicine, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama-shi, Kanagawa, 227-8501, Japan.
Department of Diagnostic Pathology, Showa University Fujigaoka Hospital, Yokohama-shi, Kanagawa, Japan.
Clin J Gastroenterol. 2020 Aug;13(4):585-590. doi: 10.1007/s12328-020-01095-7. Epub 2020 Jan 25.
Pancreatic schwannoma is difficult to diagnose preoperatively. A 79-year-old man was found to have a 9-mm pancreatic mass on abdominal ultrasonography. On EUS, there was a 9-mm, clearly demarcated, round, solid, hypo-echoic mass in the pancreatic body. The differential diagnosis included a pancreatic neuroendocrine tumor, a solid-pseudopapillary neoplasm, and an atypical pancreatic cancer. EUS-FNA was performed with a 22G needle. On pathology examination, spindle-shaped tumor cells were seen proliferating in bundles. On immunostaining, the lesion was negative for c-kit, CD34, and α-SMA but positive for S-100 protein. The MIB-1 index was < 2%. Based on the above findings, the lesion was diagnosed as a benign pancreatic schwannoma. We, therefore, decided to follow the patient with careful observation rather than resecting the lesion surgically. The tumor has not changed significantly after 3 years of follow-up. EUS-FNA is useful for the diagnosis of pancreatic schwannoma. If the tumor can be determined to be benign preoperatively, unnecessary surgery can be avoided. EUS-FNA should be actively implemented for pancreatic tumors that are difficult to diagnose definitively on imaging.
胰腺神经鞘瘤术前诊断困难。一名 79 岁男性在腹部超声检查时发现胰腺有 9mm 肿块。EUS 检查显示胰腺体部有一个 9mm 的、边界清楚的、圆形的、实性的、低回声肿块。鉴别诊断包括胰腺神经内分泌肿瘤、实性假乳头状肿瘤和非典型胰腺腺癌。使用 22G 针进行 EUS-FNA。病理检查显示，梭形肿瘤细胞呈束状增生。免疫组化染色显示，病变 c-kit、CD34 和 α-SMA 阴性，S-100 蛋白阳性。MIB-1 指数<2%。根据上述发现，病变诊断为良性胰腺神经鞘瘤。因此，我们决定密切观察患者，而不是手术切除病变。随访 3 年后，肿瘤无明显变化。EUS-FNA 有助于胰腺神经鞘瘤的诊断。如果肿瘤能在术前确定为良性，则可避免不必要的手术。对于影像学难以明确诊断的胰腺肿瘤，应积极实施 EUS-FNA。
