肝内胆管癌（iCCA）根据解剖位置、形态学表现、免疫表型和基因事件，根据世界卫生组织第五版消化系统肿瘤分类，分为大导管型（LDT）和小导管型（SDT）。我们使用真实世界数据评估了亚型分型系统，并建立了使用免疫组织化学 (IHC) 检测的补充方法。我们回顾性调查了190例手术切除的iCCA病例，并根据组织学评估和基因检测对其进行分类。根据无复发生存期（RFS）和总生存期（OS）评估IHC标志物的预后价值。基本组织学分类不充分，61例分类为不确定。该方法对 RFS 或 OS 没有预后价值。 EMA、S100P、N-cadherin、CRP四标志物IHC检测，将68例分类为LDT，108例分类为SDT，14例分类为不确定，在分型和预后方面具有较高的效率。七标记法包括CD56、MUC5AC和MUC6，与四标记法一致。根据四标记和七标记 IHC 检测，仅在 20 例 SDT iCCA 病例中检测到 FGFR2 基因融合。这种新的 iCCA 分类方法在临床实践中表现出诊断、预后和治疗价值。版权所有 © 2023。由 Elsevier B.V. 出版。

Intrahepatic cholangiocarcinoma (iCCA) is classified by the 5th WHO classification of tumours of the digestive system as large duct type (LDT) and small duct type (SDT), based on the anatomical location, morphological appearances, immunophenotype, and gene events. We evaluated the subtyping system using real-world data and established a supplementary method using immunohistochemical (IHC) detection. We retrospectively investigated 190 cases of surgically resected iCCA and classified them according to histological evaluations and gene detection. The prognostic value of the IHC markers were evaluated according to the relapse-free survival (RFS) and overall survival (OS). Basic histological classification was insufficient, with 61 cases classified as uncertain. This method showed no prognostic value for RFS or OS. The four-marker IHC detection, including EMA, S100P, N-cadherin, and CRP, which classified 68 cases as LDT, 108 cases as SDT, and 14 cases as uncertain, was highly efficient in subtyping and prognosis. The seven-marker method, including CD56, MUC5AC and MUC6, was consistent with the four-marker method. FGFR2 gene fusion was exclusively detected in 20 cases of SDT iCCA, according to the four- and seven-marker IHC detection. This novel method of iCCA classification exhibited diagnostic, prognostic and therapeutic value in clinical practice.Copyright © 2023. Published by Elsevier B.V.