To compare and analyze the conventional ultrasound and contrast-enhanced ultrasound manifestations of two subtypes of papillary renal cell carcinoma (PRCC).

A total of 27 patients who underwent surgery at the Eastern Theater General Hospital were histologically proved with PRCC from November 2014 to February 2018. According to the postoperative pathological results, the patients were divided into 16 cases with type I PRCC and 11 cases with type II. Conventional ultrasound and contrast-enhanced ultrasound examinations were performed in all cases before surgery. The conventional ultrasound and contrast-enhanced ultrasound characteristics were compared between type I and type II PRCC.

There was a statistically significant difference in the proportion of patients with typical clinical manifestations between type I and type II PRCC groups (P=0.022). The maximum diameter of type II PRCC was significantly larger than that of type I (conventional ultrasound: t=-29.31, P=0.000; contrast-enhanced ultrasound: t=-32.17, P=0.000). The boundary of type II PRCC was less clear than that of type I (P=0.002), and the shape was more irregular than that of type I (P=0.002). The growth pattern, enhancement uniformity, and enhancement of the surrounding tissues of the tumor differed significantly between type II and type I PRCC (P=0.015, 0.040, and 0.000, respectively), although there were no statistically significant differences between the two groups in terms of the location, echo, blood flow, perfusion mode, and degree of enhancement of the mass (P>0.05).

There are differences in conventional ultrasound and contrast-enhanced ultrasound characteristics between the two subtypes of PRCC. The combination of conventional ultrasound and contrast-enhanced ultrasound can provide imaging evidence for the identification of the two subtypes, which can help in the selection of surgical procedure and prognostic evaluation.