From the Department of Pathology, Shanghai Jiao Tong University Medical School Affiliated Ruijin Hospital, Shanghai, China (Yang, Liu, H. Wang, J. Xu, L Zhou, Li, H. Xu, Dong, C. Wang).
the Department of Urology, Shanghai Jiao Tong University Medical School Affiliated Renji Hospital, Shanghai, China (Y. Xu).
Arch Pathol Lab Med. 2024 Dec 1;148(12):1358-1364. doi: 10.5858/arpa.2023-0330-OA.
CONTEXT.—: Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) rarely exhibits a predominant tubulocystic architecture with few other components. RCC with pure tubules and cysts lined by eosinophilic tumor cells with prominent nucleoli would raise the diagnosis of tubulocystic RCC. It is important to differentiate the 2 entities because they lead to different outcomes.
OBJECTIVE.—: To address this concern, a multicenter study was implemented to explore useful clinicopathologic features in differentiation between tubulocystic FH-deficient RCC and tubulocystic RCC.
DESIGN.—: Clinical factors included age, sex, tumor size, and outcome. Morphologic factors included cell morphology, presence or absence of a nontubulocystic component, and stromal findings. Immunohistochemistry, fluorescence in situ hybridization, and next-generation sequencing were performed to explore the protein expression and molecular profiles of the 2 entities.
RESULTS.—: We evaluated 6 patients with tubulocystic RCC and 10 patients with tubulocystic FH-deficient RCC. Tubulocystic RCC exhibited a small size (<4.0 cm, pT1a), low Ki-67 index (<5%), retained FH, and negative 2SC expression. Tubulocystic FH-deficient RCC had a relatively large size and a high Ki-67 index. Perinucleolar haloes, loss of FH, and 2SC positivity were always observed. Pure tubulocystic architecture was not observed in FH-deficient RCC, because focal nontubulocystic components can always be seen.
CONCLUSIONS.—: We emphasized multiple sectioning to identify a nontubulocystic architecture to exclude tubulocystic RCC. Moreover, tumor size, FH/2SC staining, and the Ki-67 index can differentiate tubulocystic FH-deficient RCC from tubulocystic RCC. The diagnosis of tubulocystic RCC was not recommended in renal mass biopsy because of the limited tissues sampled.
乏鉤酸水合酶（FH）缺陷型肾细胞癌（RCC）很少表现出以小管囊状结构为主，伴有少量其他成分的特征。单纯由嗜酸粒细胞肿瘤细胞排列的小管和囊腔组成，核仁明显的 RCC 会引起对小管囊状 RCC 的诊断。区分这两种实体非常重要，因为它们会导致不同的结果。
为了解决这一问题，进行了一项多中心研究，以探讨在鉴别乏鉤酸水合酶缺陷型小管囊状 RCC 和单纯小管囊状 RCC 中的有用临床病理特征。
临床因素包括年龄、性别、肿瘤大小和结果。形态学因素包括细胞形态、是否存在非小管囊状成分以及基质发现。进行免疫组织化学、荧光原位杂交和下一代测序，以探讨这两种实体的蛋白表达和分子谱。
我们评估了 6 例单纯小管囊状 RCC 和 10 例乏鉤酸水合酶缺陷型小管囊状 RCC 患者。单纯小管囊状 RCC 体积较小（<4.0cm，pT1a），Ki-67 指数较低（<5%），保留 FH，2SC 表达阴性。乏鉤酸水合酶缺陷型小管囊状 RCC 体积相对较大，Ki-67 指数较高。核周晕圈、FH 缺失和 2SC 阳性总是可见。乏鉤酸水合酶缺陷型 RCC 中未观察到单纯小管囊状结构，因为总是可以看到局灶性非小管囊状成分。
我们强调多切片以识别非小管囊状结构，以排除单纯小管囊状 RCC。此外，肿瘤大小、FH/2SC 染色和 Ki-67 指数可区分乏鉤酸水合酶缺陷型小管囊状 RCC 和单纯小管囊状 RCC。不建议在肾肿块活检中诊断单纯小管囊状 RCC，因为取样的组织有限。
