Background: Synchronous primary cortical tumors of different histology in the same kidney are rare. Preoperative awareness of this coexistence is important, since it can help in planning the surgical approach.
Purpose: To describe the imaging findings observed in five patients with two parenchymal malignant tumors of different histology in the same kidney.
Material and methods: We reviewed the pathology reports of 381 patients operated for renal tumors from January 2000 to March 2007. The medical records of all patients with multiple, synchronous, primary lesions of different histology in the same kidney were reviewed with special attention to imaging findings and indications on the nature of the disease process. Computed tomography (CT) examinations were retrospectively evaluated for tumor detection, size, location, and enhancement pattern.
Results: We found seven patients with synchronous tumors of different histology in the same kidney (1.8%). Among these, five (1.3%) had two malignancies of different subtypes and represent our study group. Four had preoperative ultrasound; all had CT. Imaging allowed identification of multifocality in 4/5 cases and, in 3/4 patients with visible double tumors, recognition of differences in lesion appearance. In only one patient did the two tumors have similar enhancement patterns.
Conclusion: It is possible to suspect preoperatively the presence of tumors of different histologic subtypes within the same kidney. Imaging findings may provide information regarding the presence of lesions with different aggressiveness within the kidney, which may be helpful in therapeutic planning.