Johns Hopkins University School of Medicine, Pathology, Baltimore, MD, USA.
Memorial Sloan Kettering Cancer Center, Pathology, New York, NY, USA.
Histopathology. 2018 Mar;72(4):588-600. doi: 10.1111/his.13395. Epub 2017 Dec 4.
We sought to determine if some unclassified renal cell carcinomas (RCCs) in children and young adults that are characterised by predominantly eosinophilic cytoplasm are related to the recently described succinate dehydrogenase (SDH)-deficient RCC, fumarate hydratase (FH)-deficient RCC or eosinophilic solid and cystic (ESC) RCC.
We reviewed 33 unclassified RCCs with predominantly eosinophilic cytoplasm in patients aged 35 years or younger. Immunohistochemistry (IHC) for SDHB, FH and CK20 (a marker of ESC) was performed in all cases. IHC for 2-succinocysteine (2SC) was performed on RCC with loss of FH labelling. Four RCC (12%) (median age 18 years) demonstrated loss of FH labelling as well as aberrant 2SC labelling, and were thus classified as FH-deficient RCCs. Importantly, none of these cases demonstrated the characteristic macronucleoli typical of FH-deficient RCC. Eight RCC (24%) (median age 20.5 years) demonstrated loss of SDHB and were reclassified as SDH-deficient RCCs. Importantly, only four of eight SDH-deficient RCC demonstrated the characteristic cytoplasmic vacuoles and inclusions of typical SDH-deficient RCC. Ten RCC (30%) (median age 27 years) were reclassified as ESC RCCs. Four of 10 ESC RCC were multifocal (one bilateral), four of 10 ESC RCC occurred in males and one patient presented with liver and lung metastases, all not described previously in ESC. Eleven RCC (33%) remained unclassified.
Pathologists should have a low threshold for performing FH, SDHB and CK20 IHC when confronted with unclassified eosinophilic RCC or 'oncocytoma' in young patients.
我们旨在确定一些在儿童和青年人群中具有嗜酸性细胞质为主的未分类肾细胞癌（RCC）是否与最近描述的琥珀酸脱氢酶（SDH）缺陷型 RCC、富马酸水解酶（FH）缺陷型 RCC 或嗜酸性实性和囊性（ESC）RCC 相关。
我们回顾了 33 例年龄在 35 岁以下的以嗜酸性细胞质为主的未分类 RCC 患者。所有病例均行 SDHB、FH 和 CK20（ESC 的标志物）免疫组化（IHC）检测。在 FH 标记丢失的 RCC 中进行 2-琥珀酰半胱氨酸（2SC）IHC。有 4 例 RCC（12%）（中位年龄 18 岁）表现出 FH 标记丢失以及异常的 2SC 标记，因此被归类为 FH 缺陷型 RCC。重要的是，这些病例均无 FH 缺陷型 RCC 典型的大核仁。8 例 RCC（24%）（中位年龄 20.5 岁）表现出 SDHB 丢失，并重新归类为 SDH 缺陷型 RCC。重要的是，8 例 SDH 缺陷型 RCC 中只有 4 例具有典型 SDH 缺陷型 RCC 的细胞质空泡和内含物。10 例 RCC（30%）（中位年龄 27 岁）被重新归类为 ESC RCC。10 例 ESC RCC 中有 4 例为多灶性（1 例双侧），10 例 ESC RCC 中有 4 例发生于男性，1 例患者出现肝和肺转移，这些均未在 ESC 中报道过。11 例 RCC（33%）仍未分类。
病理医生在面对年轻患者的未分类嗜酸性 RCC 或“嗜酸细胞瘤”时，应降低进行 FH、SDHB 和 CK20 IHC 的阈值。
