Department of Pathology, The University of Chicago, Chicago, IL.
Am J Surg Pathol. 2019 Aug;43(8):1135-1144. doi: 10.1097/PAS.0000000000001255.
Renal cell carcinoma (RCC) with leiomyomatous stroma is a provisional category of RCC in the 2016 World Health Organization Classification of Tumors of the Urinary System. Microscopic examination of hematoxylin and eosin-stained sections reveals this entity to be well-circumscribed with tubulopapillary growth of cells with clear cytoplasm in a background of leiomyomatous stroma. Herein we describe the genetic features of 15 University of Chicago Medical Center archived cases with hematoxylin and eosin histology matching the provisional diagnosis. Immunohistochemical (IHC) stains revealed 1/15 of these tumors to be clear cell renal cell carcinoma (ccRCC) and 6/15 to be clear cell papillary renal cell carcinoma (ccpRCC), demonstrating the morphologic overlap with these discrete known entities. Interestingly 3/6 of the ccpRCCs had chromosome 18 gain suggesting there may be novel specific genetic changes in ccpRCC with leiomyomatous stroma. Of the remaining 8 tumors with IHC staining patterns that do not fit either ccRCC or ccpRCC only 3 of these had mutations in the recently described TCEB1 gene with concurrent monosomy of chromosome 8. These 3 cases had a somewhat unique IHC pattern that possibly could separate them from the 5 other non-ccRCC/non-ccpRCC cases. This descriptive study, although small, demonstrates the difficulty in applying the current World Health Organization provisional criteria at a single institution with suggestion of an immunohistochemcial panel that may assist in the diagnosis of TCEB1-mutated RCC with leiomyomatous stroma.
具有平滑肌样基质的肾细胞癌（RCC）是 2016 年世界卫生组织泌尿系统肿瘤分类中的一个暂定类别。苏木精和伊红染色切片的显微镜检查显示，这种实体肿瘤边界清楚，细胞呈管状乳头状生长，细胞质透明，背景为平滑肌样基质。在此，我们描述了 15 例芝加哥大学医学中心存档病例的遗传特征，这些病例的苏木精和伊红组织学与暂定诊断相匹配。免疫组织化学（IHC）染色显示，这些肿瘤中有 1/15 为透明细胞肾细胞癌（ccRCC），6/15 为透明细胞乳头状肾细胞癌（ccpRCC），表明与这些离散的已知实体存在形态学重叠。有趣的是，3/6 的 ccpRCC 存在 18 号染色体获得，表明在具有平滑肌样基质的 ccpRCC 中可能存在新的特定遗传变化。其余 8 个 IHC 染色模式既不符合 ccRCC 也不符合 ccpRCC 的肿瘤中，只有 3 个肿瘤在最近描述的 TCEB1 基因中存在突变，同时 8 号染色体单体缺失。这 3 例具有独特的 IHC 模式，可能使其与其他 5 例非 ccRCC/非 ccpRCC 病例区分开来。尽管本研究规模较小，但它表明在单一机构应用当前世界卫生组织暂定标准存在困难，并提出了一个免疫组化面板，可能有助于诊断具有平滑肌样基质的 TCEB1 突变型 RCC。
