Atypical renal cysts: a clinicopathological and molecular analysis of six cases
10.3760/cma.j.cn112151-20200324-00250
- VernacularTitle:非典型肾囊肿六例临床病理和分子特征分析
- Author:
Yuan CHEN
1
;
Lin ZHONG
;
Zeran YANG
;
Guoqing RU
;
Xianglei HE
;
Xiaodong TENG
;
Ming ZHAO
Author Information
1. 浙江省人民医院 杭州医学院附属人民医院病理科 310014
- Keywords:
Renal cell carcinoma;
Atypical renal cysts;
Fluorescence in situ hybridization;
Diagnosis, differential
- From:
Chinese Journal of Pathology
2020;49(12):1249-1254
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinicopathological characteristics and molecular genetics of atypical renal cysts.Methods:Six cases of atypical renal cysts were collected from Zhejiang Provincial People′s Hospital, Hangzhou, China, between February 2014 and February 2019. The clinicopathological characteristics and disease progression were analyzed. The 3p deletion and trisomy of chromosomes 7 and 17 were detected using fluorescence in situ hybridization (FISH).Results:All of the 6 patients were male, aged 43-63 years (median: 52 years). Preoperative Bosniak classification showed 4 cases of grade Ⅱ, 1 case of grade Ⅰ and 1 of grade Ⅲ. Histologically, atypical renal cysts appeared as unilocular or multilocular cysts, lined by multilayered flattened or cuboidal-shaped clear or eosinophilic cells. They often showed short papillary projections, and lacked solid or nodular growth of the lesional cells within the wall or septa of the cysts. Histologically, these cysts could be classified into three categories: acquired cystic disease-associated renal cell carcinoma (ACKD-RCC)-like (3 cases), clear cell type (2 cases), and eosinophilic papillary type (1 case). Two cases of ACKD-RCC-like atypical renal cysts were accompanied by clear cell renal cell carcinomas. On immunohistochemical staining, ACKD-RCC-like atypical renal cysts were focally CK7+/AMACR+/CD57+, the clear-cell type atypical renal cysts were CK7+/CAⅨ+, and eosinophilic papillary type atypical renal cysts were CK7+/AMACR+. FISH analyses showed that one case of ACKD-RCC-like atypical renal cysts had trisomy 17 and one case of clear cell type had 3p deletion, while no signal abnormality was detected in the other cases. The six patients were followed up for 13 to 70 months (median: 27 months), and no evidence of renal cell carcinoma was noted.Conclusion:Atypical renal cysts are a group of lesions that are heterogeneous in clinical, histological and immunophenotypical and molecular genetic features. FISH analyses suggest that a subset of the cases may be precursors of currently known renal cell carcinomas. Extensively sampling and careful observation of the histological characteristics of the cyst wall are important for distinguishing atypical renal cysts from extensively cystic renal cell carcinomas.
