Clinical value of conventional ultrasound combined with contrast-enhanced ultrasound in diagnosis of chromophobe renal cell carcinoma / 中国医师杂志

ABSTRACT

Objective:To investigate the clinical value of conventional ultrasound combined with contrast-enhanced ultrasound (CEUS) in diagnosis of chromophobe renal cell carcinoma (ChRCC).Methods:We retrospectively analyzed the ultrasound features of 40 cases with ChRCC which were confirmed by operation and pathology from January 2012 to January 2018 in our hospital. The site, shape, size, capsule, internal echo and blood supply of the lesions were observed by routine ultrasound. Then CEUS showed the modality of enhancement, including the arrival time, peak time, peak intensity, distribution and the washout time.Results:Among the 40 cases, 38 cases were single, 2 cases were multiple, 17 cases were left kidney, 22 cases were right kidney, 1 case was double kidney. The tumors were located in the upper part of the kidney in 8 cases (20.0%), the lower part of the kidney in 9 cases (22.5%), and the middle part of the kidney in 23 cases (57.5%). One of the tumors was located in the right renal pelvis, and the lesion invaded the renal capsule in 11 cases (27.5%). The tumor was round, quasi round or oval, with clear boundary in 35 cases (87.5%), unclear boundary in 5 cases (12.5%), and the maximum diameter was 2.0-11.2 (5.1±0.8)cm. The lesions were hypoechoic in 23 cases (57.5%), isoechoic in 7 cases (17.5%), slightly hyperechoic in 7 cases (17.5%), cystic and solid mixed echo in 3 cases (7.5%), homogeneous echo in 23 cases (57.5%), heterogeneous echo in 17 cases (42.5%), and calcification in 5 cases (12.5%). Color Doppler flow imaging (CDFI) showed that blood vessels could be seen around the lesions, and no obvious blood flow signal was detected in 15 cases (37.5%) of the lesions; few star shaped blood flow signals could be detected in 12 cases (30%) of the lesions, short strip shaped blood flow signals could be detected in 7 cases (17.5%) of the lesions, and abundant blood flow signals could be seen in 6 cases (15%) of the lesions. Four patients underwent contrast-enhanced ultrasound examination at the same time. The lesions began to strengthen rapidly and evenly at the same time in the renal cortex, showing slightly low enhancement, and disappeared earlier than the renal cortex, showing a " fast forward and fast backward" perfusion mode. No tumor thrombus in draining vein, perirenal tissue and lymph node metastasis were found in all cases.Conclusions:Conventional ultrasound show ChRCC to be poor blood supply of solid tumors in the renal parenchyma, most of which are hypoechoic or isoechoic, with clear boundaries. CEUS show the lesions taking on high wash-in and wash-out, low enhancement than the surrounding renal cortex. These features are helpful for preoperative ultrasound diagnosis of ChRCC.