Chromophobe renal cell carcinoma with small cell components/neuroendocrine-like features: a clinicopathological and molecular analysis
10.3760/cma.j.cn112151-20241221-00861
- VernacularTitle:伴有小细胞成分/神经内分泌样特征嫌色性肾细胞癌的临床病理及分子学分析
- Author:
Tao TANG
1
;
Daochen CHONG
;
Wenjuan YU
;
Yanxia JIANG
;
Yujun LI
;
Wei ZHANG
Author Information
1. 海军第九七一医院病理科，青岛266071
- Publication Type:Journal Article
- Keywords:
Carcinoma, renal cell;
Chromophobe;
Small cell;
Neuroendocrine;
Diagnosis, differential;
Prognosis
- From:
Chinese Journal of Pathology
2025;54(8):831-837
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinicopathological characteristics and molecular variants of chromophobe renal cell carcinoma with small cell components/neuroendocrine-like features (ChRCC-SC/ND-L).Methods:There were 7 cases of ChRCC-SC/ND-L diagnosed by light microscopy and immunohistochemical staining were collected from the Affiliated Hospital of Qingdao University (5 cases) and 971 Hospital of the People′s Liberation Army Navy (2 cases) between January 2010 and December 2023. The clinical data, histological characteristics, and immunohistochemical staining results of the patients were summarized. Among them, 4 cases underwent whole exome sequencing.Results:Among the 7 cases, 5 cases were male and 2 cases were female. The mean age was 53 (43,58)years,with a range of 36 to 76 years. Gross examination showed that the mean maximum tumor diameter was 7.9 (6.0,9.0) cm,with a range of 5.5 to 13.0 cm. The tumors were nodular, well-defined, gray, red or yellow in color with a solid cut surface, except for 1 case with cystic and solid on cut surface. One case showed visible necrosis, and 1 case invaded the renal pelvis and sinus. Microscopically, the tumors had clear boundaries. Typical ChRCC components (5 cases of classical type, 2 cases of eosinophilic type) were found in all cases, accompanied by varying amounts of small cell components (5%-90%). The two components were mixed in 6 cases or directly adjacent to each other in 1 case. The small cell components were arranged in clusters, dense acinar and nest-like structures, beam-like, fence-like, chrysanthemum-shaped clusters, and ribbon-like patterns. Three cases exhibited patchy necrosis. Intravascular tumor thrombus was found in 1 case. Immunohistochemically, EMA was expressed consistently in the small cell and typical ChRCC components (7/7); whilst both CK7 and CD117 were negative in 1 case with typical ChRCC component (6/7). Small cell components in 3 cases were positive for CD56, whereas all 7 cases were negative for CgA, Syn, and INSM1. The Ki-67 proliferation index was less than 1% in both components. Whole exome sequencing revealed that the 4 cases exhibited different genetic aberrations including 1 case with multiple chromosomal deletions, while 2 cases showed amplification of chromosome 12 and deletion of chromosome 11, respectively. The 7 cases were followed up for 25 to 172 months. Except for 1 patient that died with unknown causes 25 months after surgery, the remaining 6 cases were still alive (average 103.8 months, median 101 months).Conclusions:ChRCC-SC/ND-L is a very rare subtype of ChRCC. The small cell component does not represent true neuroendocrine differentiation and might indicate a morphological heterogeneity of the tumor. The presence of typical chromophobe cell carcinoma components is helpful for the diagnosis of ChRCC-SC/ND-L and they do not have consistent molecular characteristics. ChRCC-SC/ND-L has a good prognosis and the small cell components/neuroendocrine-like components might not have a significant impact on the outcome of patients with the tumor.
