A case report of an uncommon presentation of Nephroblastoma (Wilms tumor): in an older child with polycythemia and elevated erythropoietin

Abstract

Abstract Introduction/Objective Wilms tumor (nephroblastoma), is a neoplasm that has a prevalence of 1 per 10,000 before the age of fifteen, with 50% occurring before age 3. WT1 (11p13) gene, a zinc finger transcription factor, is expressed in early urogenital system development and mutations here represent one of the primary pathways to the development of Wilms tumor. Although mouse model studies have shown that WT1 may be a transcriptional activator of erythropoietin (EPO) gene, increases in serum erythropoietin are rarely seen in patients with Wilms tumor. Concurrent polycythemia is a further rarity with only 11 such reports in literature. This is intriguing since WT1 mutations represent the most common mutation pathway in Wilms Tumor. Interestingly, other tumor types associated with elevated serum EPO and polycythemia (e.g. renal cell carcinoma and metanephric adenoma) are thought to do so through the generation of hypoxia inducible factor, and induction of VEGF. Methods/Case Report Here we present a case of Wilms tumor in a 7-year-old female who was establishing care after moving to Vermont. Physical examination showed possible splenomegaly ultimately discovered to be a large LUQ abdominal mass with a concurrent discovery of polycythemia. Subsequent serum EPO was 308 (Ref: 2.6-18.5 mIU/mL).). The mass was surgically removed with resolution of polycythemia. Histological evaluation showed a triphasic, blastema predominant Wilms tumor with favorable histology. Heterologous, vascular differentiation was seen in the stroma, positive for CD34 and CD31, and negative for D2-40. Results (if a Case Study enter NA) NA Conclusion Based on these findings, this phenomenon may be related to increased VEGF expression resulting in this patient’s increased serum EPO and polycythemia, and heterologous vascular differentiation within the tumor stroma. This is the first report of histology in a case of Wilms tumor associated with high serum EPO and polycythemia and may indicate an alternative pathway for the generation of EPO in Wilms tumor.