OBJECTIVE: To illustrate the imaging appearances of a spectrum of renal collision and composite tumors. Occurrence of collision and composite tumors in the genitourinary tract is rare compared to the usual occurrence of synchronous tumors. METHODS: Case studies were chosen that represent the different tumors. Analysis was made on both the imaging and the pathology if excision was performed. RESULTS: Presence of 2 different cell types can lead to confusing imaging findings, and biopsy or excision is typically needed for final diagnosis. Some composite tumors have a characteristic appearance on imaging based on their pathologic features. CONCLUSION: Familiarity with imaging findings may help radiologists include these tumors in their differential diagnosis. Published by Elsevier Inc.
OBJECTIVE: To illustrate the imaging appearances of a spectrum of renal collision and composite tumors. Occurrence of collision and composite tumors in the genitourinary tract is rare compared to the usual occurrence of synchronous tumors. METHODS: Case studies were chosen that represent the different tumors. Analysis was made on both the imaging and the pathology if excision was performed. RESULTS: Presence of 2 different cell types can lead to confusing imaging findings, and biopsy or excision is typically needed for final diagnosis. Some composite tumors have a characteristic appearance on imaging based on their pathologic features. CONCLUSION: Familiarity with imaging findings may help radiologists include these tumors in their differential diagnosis. Published by Elsevier Inc.