This 8 year-old male presented to an outside facility with a brief complaint of left flank pain and difficulty breathing. After an unsuccessful treatment for possible reactive airways disease, he was noted to have “dark urine” and taken to the local emergency department, where a non-contrast CT revealed a left renal mass and pleural effusions. He was admitted to our facility for workup, which included a CT of the chest, abdomen and pelvis. Selected images from the CT are submitted.
Coronal, sagittal, and axial views of the chest and abdomen showing the retroperitoneal involvement below the diaphragm with diffuse renal involvement and an area of sub-capsular lucency in the lower pole of the left kidney.
Rhabdoid tumors of the kidney are extremely rare; about 5-10 cases per year in the US. Most present in under 3 years of age and about 20% have synchronous or metachronous CNS tumors at time of presentation. This patient did not have CNS involvement. Overall prognosis is worst of all childhood renal tumors, poor for tumors which have non CNS metastatic disease (~20% survival) and generally better for children presenting in the older age group.
The imaging findings are very similar to Wilms tumor, except for more extensive renal involvement with areas of low, mixed attenuation and a somewhat characteristic finding of subcapsular cysts, which this patient's CT demonstrated (see arrow on axial image)ref. 3
- Caffey’s Pediatric Diagnostic Imaging, 10th edition, vol 2, pp. 1790,91