胰母细胞瘤是罕见的儿科肿瘤。在成人中，它们极为罕见，并且似乎预后更差。大多数是散发性的，尽管在家族性腺瘤病患者中偶尔会发生。与胰管腺癌不同，胰母细胞瘤不认为起源于异型前体病变。对一位患有瘤样息肉与肠道分化和低度畸形的壶腹癌患者进行了临床史、内镜、病理和分子学检查，结果显示与其中一个肿瘤相邻的地方有一个胰母细胞瘤。两个肿瘤都具有异常的p53（完全丧失）和核β-catenin免疫染色。突变分析表明它们两者都有相同的CTNNB1（p.S45P）突变。这个病例增加了我们对这些罕见肿瘤发病机制的认识，并表明其中一部分可能起源于瘤样前体。此外，这个病例是第二个从十二指肠壶腹开始的胰母细胞瘤，之前的病例表明壶腹部位会导致更早的诊断。此外，这个病例还突显了在仅有有限组织样本的情况下诊断胰母细胞瘤的困难，并说明有必要在所有在胰腺周围的肿瘤中，包括成年患者中的肿瘤，将胰母细胞瘤纳入鉴别诊断的范围内。版权所有©2023 Wolters Kluwer Health，Inc.保留所有权利。

Pancreatoblastomas are rare pediatric tumors. In adults, they are exceedingly rare and seem to have a worse prognosis. Most are sporadic, though rare, cases occur in patients with familial adenomatous polyposis. Unlike pancreatic ductal adenocarcinomas, pancreatoblastomas are not believed to arise from dysplastic precursor lesions. Clinical history, along with endoscopic, pathological, and molecular findings, was reviewed for a 57-year-old male patient with an ampullary mass who presented with obstructive jaundice. Microscopic examination showed a pancreatoblastoma subjacent to an adenomatous polyp with intestinal differentiation and low-grade dysplasia. Both tumors had abnormal p53 (complete loss) and nuclear β-catenin immunostaining. Mutational panel analysis showed an identical CTNNB1 (p.S45P) mutation in both. This case adds to our understanding of the pathogenesis of these rare tumors and suggests that a subset may arise from an adenomatous precursor. In addition, this case is just the second pancreatoblastoma to originate in the duodenal ampulla, and the preceding case suggests that an ampullary location leads to earlier diagnosis. Moreover, this case highlights the difficulty in diagnosing pancreatoblastoma on limited tissue specimens and illustrates the need to include pancreatoblastoma in the differential diagnosis in all tumors in and around the pancreas, including those in adult patients.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.