Ultrasound Imaging of Cystic Nephroma

Abstract

Cystic nephroma is a rare, benign multicystic lesion of the kidney. This tumor occurs both in children and in adults. In children, it is highly prevalent in males; in adults, it is more frequent in women. The term "cystic nephroma" represents two apparently different entities: pediatric cystic nephroma, a benign form thought to originate from metanephric tissue, and adult cystic nephroma, considered as a lesion of mixed epithelial stromal tumor. The clinical presentation may be a palpable mass or nonspecific symptoms such as abdominal pain, hematuria, and urinary tract infections. In this review, we summarize the ultrasound imaging features of cystic nephroma and describe the characteristics of the most common renal cystic lesions and the differential diagnosis of cystic nephroma with other renal cystic lesions.

Keywords: DICER1; cystic nephroma; cystic renal cell carcinoma; mixed epithelial stromal tumor; renal cystic lesions.

Figure 1

Macroscopic examination of bilateral CN of a 5-month-old male. Image provided by Professor Ellen M. Chung and Director Donald E. Hatley Jr.

Figure 2

Renal US of a 5-month-old male (same patient of Figure 1). The images show the presence of bilateral CN that appears as multiloculated cystic lesions, with margins well circumscribed by the surrounding renal parenchyma and internal septa. Caliectasies are also present. Image provided by Professor Ellen M. Chung and Director Donald E. Hatley Jr.

Figure 3

Unenhanced CT axial scan (a), CT axial scan during arterial (b), venous (c), and nephrographic (after 180 seconds from the contrast medium injection) (d) phases of a 44-year-old male, showing the presence of an oval, partially esophytic lesion with predominantly fluid-corpusculated content and internal septa. Cytological and histological examination have placed the diagnosis of clear cell renal cell carcinoma.

Figure 4

CT axial scan during arterial phase of a 44-year-old male (same patient of Figure 3) shows a minute hypervascular solid component located in the cranial portion of the clear cell renal cell carcinoma.