Abstract：
BACKGROUND: In the transplant setting, the definition of the risk of neoplastic transmission from donor to recipient often requires intraoperative pathological evaluation on frozen sections. Although most lesions can be easily classified into acceptable or unacceptable risk according to the Italian National Guidelines, there are cases in which unusual histologic features cannot be further investigated because of the lack of ancillary techniques on frozen sections.
METHODS: Here we present a case of a liver lesion in a 51-year-old male donor, subjected to histopathological on-call examination. The frozen sections showed a well-demarcated lesion consisting of epithelioid cells disposed in laminar structures and intermingled with a dense lymphocytic population: this led to organ discard with interruption of the donation process. The definitive histological analysis required an extensive immunohistochemical (IHC) investigation: the final diagnosis was \"bile duct adenoma with oncocytic features\", eventually confirmed by a strongly positive anti-mitochondrial IHC. Finally, an NGS panel analysis was performed, which revealed NRAS mutation.
CONCLUSIONS: To the best of our knowledge, this is the first case of oncocytic bile duct adenoma confirmed by anti-mitochondrial IHC and with NRAS mutation. The most challenging aspect of this case was represented by the transplant setting. In fact, the oncocytic features and the dense lymphocytic infiltrate represented concomitant unusual histological features that led to the halt of the organ donation procedures.
METHODS: Here we present a case of a liver lesion in a 51-year-old male donor, subjected to histopathological on-call examination. The frozen sections showed a well-demarcated lesion consisting of epithelioid cells disposed in laminar structures and intermingled with a dense lymphocytic population: this led to organ discard with interruption of the donation process. The definitive histological analysis required an extensive immunohistochemical (IHC) investigation: the final diagnosis was \"bile duct adenoma with oncocytic features\", eventually confirmed by a strongly positive anti-mitochondrial IHC. Finally, an NGS panel analysis was performed, which revealed NRAS mutation.
CONCLUSIONS: To the best of our knowledge, this is the first case of oncocytic bile duct adenoma confirmed by anti-mitochondrial IHC and with NRAS mutation. The most challenging aspect of this case was represented by the transplant setting. In fact, the oncocytic features and the dense lymphocytic infiltrate represented concomitant unusual histological features that led to the halt of the organ donation procedures.
摘要：
背景：在移植设置中，肿瘤从供体到受体传播风险的定义通常需要对冰冻切片进行术中病理评估.尽管根据意大利国家指南，大多数病变可以很容易地分为可接受或不可接受的风险，在某些情况下，由于缺乏冷冻切片的辅助技术，无法进一步研究异常的组织学特征。
方法：这里我们介绍一例51岁男性供者肝脏病变的病例，接受组织病理学随叫随到的检查。冷冻切片显示出界限分明的病变，该病变由位于层状结构中的上皮样细胞组成，并与密集的淋巴细胞群混合在一起：这导致器官丢弃，并中断了捐赠过程。明确的组织学分析需要进行广泛的免疫组织化学（IHC）研究：最终诊断为“具有嗜酸细胞特征的胆管腺瘤”，最终通过强阳性抗线粒体IHC证实。最后,进行了NGS面板分析，这揭示了NRAS突变。
结论：据我们所知，这是首例经抗线粒体IHC证实并伴有NRAS突变的嗜酸细胞性胆管腺瘤.这种情况下最具挑战性的方面是移植设置。事实上,嗜酸细胞特征和密集淋巴细胞浸润是伴随的异常组织学特征，导致器官捐赠程序停止。
方法：这里我们介绍一例51岁男性供者肝脏病变的病例，接受组织病理学随叫随到的检查。冷冻切片显示出界限分明的病变，该病变由位于层状结构中的上皮样细胞组成，并与密集的淋巴细胞群混合在一起：这导致器官丢弃，并中断了捐赠过程。明确的组织学分析需要进行广泛的免疫组织化学（IHC）研究：最终诊断为“具有嗜酸细胞特征的胆管腺瘤”，最终通过强阳性抗线粒体IHC证实。最后,进行了NGS面板分析，这揭示了NRAS突变。
结论：据我们所知，这是首例经抗线粒体IHC证实并伴有NRAS突变的嗜酸细胞性胆管腺瘤.这种情况下最具挑战性的方面是移植设置。事实上,嗜酸细胞特征和密集淋巴细胞浸润是伴随的异常组织学特征，导致器官捐赠程序停止。
