ABSTRACT
Objective:To compare the imaging features of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) with chromophobe RCC.Methods:From November 2016 to January 2020, 28 patients with Xp11.2 RCC and 28 patients with chromophobe RCC confirmed by pathology were retrospectively analyzed in Peking University First Hospital. All 23 patients underwent preoperative CT examination, and 5 patients underwent routine MRI in each group. The clinical and imaging features were observed and recorded. The CT features including side, location, size, boundary, shape, uniform density, composition (solid, cystic-solid, cystic), hemorrhage, calcification, lymph node metastasis of the lesions and distant metastasis were observed, and the CT value of the solid part of the tumor at each stage was measured. On MRI images, the signal of the lesion in each sequence and enhancement mode were observed. The differences in clinical and imaging characteristics between the 2 groups were compared using independent samples t test or χ 2 test. Results:The Xp11.2 RCC more frequently affected young [(27±10) years] patients, while chromophobe RCC more frequently involved middle-aged [(37±7) years] patients asymptomatically, and the difference was statistically significant ( t=-4.99, P<0.001). The lesion size of Xp11.2 RCC [(5.4±2.2) cm] were significantly smaller than that of chromophobe RCC [(6.9±1.8) cm] ( t=-2.93, P=0.005). There were significant differences in the density and composition of lesions between Xp11.2 RCC and chromophobe RCC (χ 2=4.60, 18.67, P=0.032,<0.001). There were no significant differences in the side, location, boundary, shape, hemorrhage, calcification, fat, lymph node metastasis and distant metastasis between the 2 kind of lesions (all P>0.05). The CT values of solid components in Xp11.2 RCC in cortico-medullary phase and delayed phase were higher than those in chromophobe RCC, and the difference were statistically significant ( t=11.80, 20.15, both P<0.001). Five cases of Xp11.2 RCC showed iso- or slightly hyperintense signal on T 1WI and slightly hypointense signal on T 2WI. Two cases showed delayed enhancement after enhancement, and 3 cases showed a slight decrease in delayed phase enhancement. Conclusion:Compared with chromophobe RCC, Xp11.2 RCC has certain characteristics in imaging manifestations (lesion size, density uniformity, composition, CT value of post-enhanced cortico-medullary phase and delayed phase). Imaging manifestations combining the clinical manifestations (age of onset) are helpful for preoperative diagnosis of Xp11.2 RCC.
ABSTRACT
Objective:To summary the problems that may be encountered in the diagnosis of Xp11.2 translocation/TFE3 gene fusion associated renal cell carcinomas (Xp11 RCC) and to improve the understanding and diagnostic level.Methods:The clinical and pathological data of 5 children with Xp11 RCC pathologically diagnosed in Children′s Hospital of Capital Institute of Pediatrics from January 2015 to December 2019 were collected for retrospective analysis.Results:The 5 cases included 2 males and 3 females with the age of 4-8 years old.All cases presented with abdominal mass.Four cases received radical nephrectomy and radical tumor resection, and 1 case received simple tumor resection after related examination.Routine HE staining, immunohistochemical staining and fluorescence in situ hybridi-zation (FISH) were performed after surgery.The histological morphology of tumor was varied, and the tumor cells were arranged in nest flake, acinar or papillary pattern, with abundant cytoplasm form completely transparent to eosinophilic staining (pink), and gravel-like calcification was visible.Micropapillary arranged tumor cells appeared in 1 case besides classic pattern; in another case, the tumor cells were highly eosinophilic with abundant cytoplasm and visible round or elliptic eosinophilic bodies.The tumor cells in 5 cases showed diffuse and strong expression of TFE3, and FISH assay showed abnormal separation signal.Conclusions:Xp11 RCC is a relatively rare renal malignant tumor with diverse histological morphology, which should be distinguished from other common renal tumors in children.Its immunohistochemical expression and molecular detection are of specificity, and it should be diagnosed based on clinical incidence.
ABSTRACT
We represent a pathologically proven case of a four-year-old male patient with renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion, which is rare but more frequent in children or young adults. Computed tomography showed about 2.5 cm size ill-defined mass in the right kidney. The mass was hyperechoic on ultrasound. Magnetic resonance imaging demonstrated a mass with capsular enhancement and diffusion restriction. We present a case of Xp11.2 renal cell carcinoma and provide review of the literature.