Extrarenal Wilms' Tumor of the Ovary: A Case Report and Short Review of the Literature

Background: Wilms' tumor is a renal malignancy commonly occurring in childhood, with classic histologic features. Extrarenal Wilms' tumor is extremely rare, and only a few isolated cases have been described in the literature in the retroperitoneum, inguinal region, uterus, cervix, ovaries, skin, mediastinum, and chest wall. Case: A 14-month-old child presented with abdominal distention and a palpable mass in the right lower abdomen. Histologically, glomeruloid and tubular structures were seen within sheets of undifferentiated blastemal component. No teratomatous components were identified, despite extensive sampling, whereas a rim of ovarian tissue was present in one of the sections. Results: A diagnosis of primary ovarian Wilms' tumor was made. The patient was given chemotherapy and continues to be followed. Conclusions: Although very rare, Wilms' tumor may occur in sites other than the kidney and should also be considered as one of the differential diagnoses of an abdominal mass in children. Similar staging and treatment protocol to those for renal Wilms' tumor can be followed.