Fatty Wilms' tumor versus teratoma in a horseshoe kidney. Differential diagnosis

In children with horseshoe kidneys Wilms' tumors can be observed 2 to 8-tim es more often. Wilms' tumors are malignant mixed tissue tumors that seldom show large parts of fatty tissue. We report about a 28-month-old girl with an unusual Wilms' tumor in a horseshoe kidney which according to radiologic al criteria could have been a teratoma because of its large lipomatous part with internal calcifications. The radiological characteristics of these di fferential diagnoses are presented in different cross-section imagings. Bot h differential diagnostic considerations correlated with the histologic dia gnosis of a teratoid Wilms' tumor. Discussion: The presented case is to emphasize the differential diagnosis W ilms' tumor versus teratoma is not just difficult for the radiologist betwe en sometimes for the histologist.