Malignant Mixed Germ Cell Tumor of the Testis with Associated Nephroblastoma: A Rare Entity

Abstract

Abstract Introduction/Objective While nephroblastoma is the most common primary childhood renal malignancy, it rarely occurs at extra-renal sites. Testicular nephroblastoma is exceedingly rare, with only 5 previously reported cases arising in association with primary testicular teratoma (4 of which arising in non-atrophic, and 1 arising in atrophic testis). We report a case of testicular nephroblastoma with multiple associated germ cell components. Methods/Case Report The case is that of a 28-year-old male presenting with an enlarging, painless right scrotal swelling. Laboratory results showed elevated serum AFP with normal LDH and beta-HCG, and imaging confirmed the presence of a heterogenous testicular mass. A radical orchiectomy was performed, revealing a tan-white, fleshy, nodular 5.5 cm mass almost entirely replacing the testicular parenchyma. Microscopically, the tumor consisted of multiple components. The nephroblastoma component was associated with teratoma with immature elements and consisted of epithelial tubular structures, small blue blastemal cells, and pale mesenchymal stroma which demonstrated pan-cytokeratin and patchy WT1 expression by immunohistochemistry. Additional components included yolk sac tumor and minor component of seminoma. Foci of germ cell neoplasia in-situ were also identified, supported by immunohistochemical stains for PLAP and OCT3/4. The patient’s post-resection tumor markers normalized, and further assessment for metastasis and chemotherapy is pending. Results (if a Case Study enter NA) NA Conclusion Malignant mixed germ cell tumors of the testis with associated nephroblastoma are exceedingly rare, further studies nand followup are required to determine prognostic values and achieve a more complete understanding of this combination of entities.