Malignant renal tumors in children

Abstract

Renal malignancies are common in children. While the majority of malignant renal masses are secondary to Wilms tumor, it can be challenging to distinguish from more aggressive renal masses. For suspicious renal lesions, it is crucial to ensure prompt diagnosis in order to select the appropriate surgical procedure and treatment. This review article will discuss the common differential diagnosis that can be encountered when evaluating a suspicious renal mass in the pediatric population. This includes clear cell sarcoma of the kidney, malignant rhabdoid tumor, renal medullary carcinoma and lymphoma.

Figure 1.

A, Large left renal mass in a 4-year old female with central areas of necrosis (arrow). Diagnosis was Wilms tumor on surgical pathology; B, Three-year old female with a left renal mass (Wilms tumor) with associated retroperitoneal lymphadenopathy (long arrow). There is also extracapsular extension of the tumor (short arrow). C, CT of the chest showed multiple metastatic pulmonary nodules; D, Five-year old female with bilateral Wilms tumor. Large left renal mass and a smaller right renal mass (arrow). Bilateral partial nephrectomies were performed; E, Nephroblastomatosis. Eighteen-month old female with an enlarged abdomen. Axial post contrast MRI shows bilateral nephromegaly containing multiple lobulated parenchymal masses with streaky enhancement; F, Six-year old female with a right renal mass (arrow). This was a renal cell carcinoma on surgical pathology after nephrectomy.

Figure 2.

A, Ten-year old African-American male with sickle-cell trait. Coronal CT scan shows a centrally located and infiltrating left renal mass. Nephrectomy was performed and surgical pathology came back as renal medullary carcinoma. B, Large right renal mass in a 7-month old male. Nephrectomy was performed and the surgical pathology revealed a rhabdoid tumor. C, Two -year old male with a large left renal mass indistinguishable from a Wilms tumor. The mass was a clear cell sarcoma on surgical pathology. D, Four-year old female with history of abdominal enlargement. The kidneys are enlarged and show multiple hypodensities. There are also enlarged retroperitoneal lymph nodes (arrow); E, Follow-up CT 5 months later after chemotherapy showing normal kidneys and resolution of the retoperitoneal lymphadenopathy.