Von Hippel-Lindau disease: A Case Report

Von Hippel-Lindau disease is an autosomal dominant disorder characterized by the presence of multiple benign and malignant tumors including hemangioblastomas of the retina and central nervous system, pancreatic cysts and tumors, renal cell carcinomas, pheochromocytomas and epididymal cystadenomas. We report the radiologic findings of a case of von Hippel-Lindau disease, describing the family history.

Radiologic Differentiation Between Homogeneously Solid Renal Cell Carcinoma and Muscle-Predominant Renal Angiomyolipoma

PURPOSE: To compare the differential radiologic findings of renal cell carcinoma presenting as a homogeneous solid mass (HS-RCC) and muscle-predominant angiomyolipoma (MP-AML). MATERIALS AND METHODS: Nine of 76 surgically and pathologically proven RCCs presenting at CT or magnetic resonance (MR) imaging as a homogeneous solid mass, and four cases of MP-AML were included in this study. Echogenicity at sonography, attenuation at non-enhanced CT (NECT), the contour of the mass, signal intensities at T1- and T2-weighted MR imaging, the existence of a capsule, and the pattern and degree of enhancement at CT and MR imaging were retrospectively analyzed. RESULTS: Two of five HS-RCCs were isoechoic and three were hyperechoic. Two of three MP-AMLs, however, were isoechoic, and one was mixed echoic. All nine HS-RCCs were round or oval in shape, but three MPAMLs were lobulated and one was round. At NECT, seven of eight HS-RCCs were isodense and one was hypodense compared to surrounding normal renal parenchyme, but three MP-AMLs were hyperdense masses and one was isodense. At enhanced CT, HS-RCCs showed various degrees of homogeneous enhancement, but all MP-AMLs showed moderate homogeneous enhancement. All three MP-AMLs demonstrated heterogeneous hypointensity at T2-weighted MRI and homogeneous hypointensity at T1-weighted MRI. HS-RCCs showed various signal intensities at both T1- and T2-weighted MRI, and in five cases, heterogeneous high signal intensity at T2-weighted MRI. Capsules were observed in seven of nine HS-RCCs but not in any of the three MP-AMLs. At enhanced T1-weighted MRI, MP-AMLs showed mild to moderate enhancement, but HSRCCs showed mild, moderate, and strong enhancement in two, two, and five cases, respectively. CONCLUSION: Echogenicity, density at NECT, signal intensity at MR T2-WI, the contour of the mass, and the existence of a capsule are features which are useful in the differential diagnosis of HS-RCC and MP-AML.

MR Imaging Findings of Renal Capsular Leiomyoma: A Case Report

In the literature, descriptions of the MR findings of renal leiomyoma are rare. We present the MR findings ofa capsular leiomyoma of the kidney in which hy pointensity relative to normal renal parenchyma was seen on bothT1- and T2-weighted MR images.

Patchy signal within Venous Tumo Thrombusin Patients with Renal Cell Carcinoma: A Helpful MR Sign suggestingTumor Neovascularity

PURPOSE: Tumoral neovascularity characteristic of venous invasion of renal cell carcinoma has been demonstrated using angiography, computed tomography, and color Doppler duplex ultrasonography. Previous reports on the characteristic findings of MR imaging have, however, been sporadic. The purpose of this study was to evaluate the usefulness of a patchy signal seen on MR images within the venous thrombus of renal cell carcinoma as a sign of tumor neovascularity. MATERIALS AND METHODS: Six patients with histopathologically-proven unilateral renal cell carcinoma (right:left=3:3) with venous tumor thrombi were included in this study. MR imaging findings were retrospectively analyzed with respect to the presence of patchy signals within a thrombus in a renal vein, the IVC, or the right atrium. MR imaging findings on spin-echo and gradient-echo images were compared with histopathologic findings especially in terms of tumor neovascularity. RESULTS: On histopathologic examination, a tumor thrombus was found in the renal vein in three patients, in the IVC in six, and within the right atrium in two. Patchy signals were demonstrated on MR images in one of three patients with renal vein invasion, in four of six with IVC invasion, and in both patients with right atrial invasion. CONCLUSION: On MR imaging, a patchy signal within a venous thrombus is a helpful sign suggesting tumor neovascularity, one of the characteristics of venous invasion by renal cell carcinoma.

Renal Cell Carcinoma in Adult Polycystic Kidney Disease: A Case Report

The authors report a case of a renal cell carcinoma occurring in an adult suffering from polycystic kidney disease and diagnosed by radiologic examination. The patient presented with palpable flank mass, hematuria and weight loss. Ultrasonography, CT, MRI and angiography were performed preoperetively. Although severe renal architectural distortion and destruction caused by polycystic disease had masked evidence of malignancy, this was diagnosed after examination of the solid component of the mass lesion, and its hypervascular character, as seen on the three types of radiologic image. Malignancy was confirmed through nephrectomy and pathological examination.