Institute of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg, University Hospital, Erlangen, Germany.
Institute of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg, University Hospital, Erlangen, Germany.
Semin Diagn Pathol. 2021 Nov;38(6):152-162. doi: 10.1053/j.semdp.2021.09.004. Epub 2021 Sep 20.
Loss of the morphological and immunophenotypic characteristics of a neoplasm is a well-known phenomenon in surgical pathology and occurs across different tumor types in almost all organs. This process may be either partial, characterized by transition from well differentiated to undifferentiated tumor component (=dedifferentiated carcinomas) or complete (=undifferentiated carcinomas). Diagnosis of undifferentiated carcinoma is significantly influenced by the extent of sampling. Although the concept of undifferentiated and dedifferentiated carcinoma has been well established for other organs (e.g. endometrium), it still has not been fully defined for urological carcinomas. Accordingly, undifferentiated/ dedifferentiated genitourinary carcinomas are typically lumped into the spectrum of poorly differentiated, sarcomatoid, or unclassified (NOS) carcinomas. In the kidney, dedifferentiation occurs across all subtypes of renal cell carcinoma (RCC), but certain genetically defined RCC types (SDH-, FH- and PBRM1- deficient RCC) seem to have inherent tendency to dedifferentiate. Histologically, the undifferentiated component displays variable combination of four patterns: spindle cells, pleomorphic giant cells, rhabdoid cells, and undifferentiated monomorphic cells with/without prominent osteoclastic giant cells. Any of these may occasionally be associated with heterologous mesenchymal component/s. Their immunophenotype is often simple with expression of vimentin and variably pankeratin or EMA. Precise subtyping of undifferentiated (urothelial versus RCC and the exact underlying RCC subtype) is best done by thorough sampling supplemented as necessary by immunohistochemistry (e.g. FH, SDHB, ALK) and/ or molecular studies. This review discusses the morphological and molecular genetic spectrum and the recent develoments on the topic of dedifferentiated and undifferentiated genitourinary carcinomas.
肿瘤形态和免疫表型特征的丧失是外科病理学中众所周知的现象，几乎发生在所有器官的不同肿瘤类型中。这个过程可能是部分的，表现为从分化良好的肿瘤成分向未分化肿瘤成分的转变（=去分化癌），也可能是完全的（=未分化癌）。未分化癌的诊断明显受采样范围的影响。尽管未分化和去分化癌的概念已经在其他器官（如子宫内膜）中得到很好的确立，但它在泌尿系统癌中尚未得到充分定义。因此，未分化/去分化泌尿生殖系统癌通常被归入低分化、肉瘤样或未分类（NOS）癌的范畴。在肾脏中，去分化发生在所有肾细胞癌（RCC）亚型中，但某些具有明确遗传定义的 RCC 类型（SDH-、FH-和 PBRM1-缺陷型 RCC）似乎具有内在的去分化倾向。组织学上，未分化成分显示出四种模式的可变组合：梭形细胞、多形性巨细胞、横纹肌样细胞和未分化的单形性细胞，伴有/不伴有明显的破骨细胞样巨细胞。其中任何一种偶尔都可能与异源间充质成分相关。它们的免疫表型通常较为简单，表达波形蛋白和不同程度的细胞角蛋白或 EMA。通过彻底的采样，并根据需要补充免疫组织化学（例如 FH、SDHB、ALK）和/或分子研究，对未分化癌（尿路上皮与 RCC 以及确切的 RCC 亚型）进行精确的亚分型是最好的。本文综述了去分化和未分化泌尿生殖系统癌的形态学和分子遗传学谱以及该主题的最新进展。
