A 28-month-old boy presents with a palpable lump in the left abdomen, first noticed one week prior.
Images from contrast-enhanced CT of the abdomen are shown below.
- There is a mass arising from the left adrenal gland.
2.There is a hypodense left para-aortic lymph node.
3.There is associated retroperitoneal hemorrhage.
CT also demonstrates a destructive lesion in the L1 vertebral body (not shown in previous images).
4.Which of the following is the most likely diagnosis given the presence of osseous metastasis, the imaging findings, and patient demographics?
Renal cell carcinoma
5.Stage I and II disease for the above diagnosis are defined by imaging features.
6.Which of the following is the most common location for metastasis of the above tumor?
Regional lymph nodes
Axial and coronal contrast-enhanced CT images of the abdomen demonstrate a large well-circumscribed mass arising from the left renal medulla with mass effect upon and associated claw sign from the adjacent renal parenchyma. The mass demonstrates heterogeneous enhancement with large hypoattenuating components, corresponding areas of necrosis, and cystic change. The left adrenal gland is separately identified and normal in appearance (image 1). There is a hypodense left para-aortic lymph node (image 3), corresponding to nodal metastasis. No masses are seen in the contralateral kidney.
- Clear-cell sarcoma
- Wilms\’ tumor
- Primitive neuroectodermal tumor
- Renal cell carcinoma
- Mesoblastic nephroma
Clear-cell sarcoma of the kidney (CCSK)
7.Clear-cell sarcoma of the kidney is most commonly diagnosed at which of the following ages?
Younger than 6 months
2 to 4 years
6 to 10 years
12 to 18 years
8.Which of the following syndromes/conditions has a strong association with clear-cell sarcoma of the kidney?
Cross fused renal ectopia
None of the above
9.Which of the following neoplasms is derived from the renal medulla?
Renal cell carcinoma
Clear-cell sarcoma of the kidney
10.Which of the following statements is FALSE?
Prognosis of clear-cell sarcoma of the kidney was historically worse than Wilms\’ tumor.
Clear-cell sarcoma of the kidney is more often bilateral than Wilms\’ tumor.
Staging for clear-cell sarcoma of the kidney is based on surgical pathology.
Presence of osseous metastases corresponds to stage IV disease.
11.Which of the following chemotherapies is added to the standard regimen for patients with stage IV disease?
- Clear-cell sarcoma
- Regional lymph nodes
- 2 to 4 years
- None of the above
- Clear-cell sarcoma of the kidney
- Clear-cell sarcoma of the kidney is more often bilateral than Wilms\’ tumor.
- Clear-cell sarcoma of the kidney is a rare, primary pediatric renal malignancy.
- Histology: There are several variants, the most common of which is myxoid type, although most tumors have a mix of different histologic types.
Staging is according to the National Wilms\’ Tumor Study system:
- I: Organ-confined tumor, intact renal capsule, no involvement of vessels, and no residual tumor at surgical margins.
- II: Tumor extension beyond renal capsule but still completely resected, no residual tumor at surgical margins, tumor can involve vessels in the renal sinus, and spillage of tumor during surgery or biopsy to the flank
- III: Unresectable primary tumor, lymph node metastases, residual tumor at surgical margins, tumor spillage into peritoneal surfaces
- IV: Hematogenous spread to distant organs or extra-abdominal lymph nodes
- Classically associated with metastases to bone and brain:可转移至骨骼和脑：
- Osseous metastases have been reported in 40% to 60% cases, which is much higher than the prevalence in Wilms\’ tumor (therefore, a useful feature to guide the differential diagnosis during initial evaluation).
- Rates of metastases have decreased with current, more aggressive chemotherapy regimens, but the percentage of recurrent metastases occurring in the brain are increasing due to relatively poor penetration of systemic cytotoxic agents (as compared with extracranial disease).
- Most prevalent location for metastases at presentation are lymph nodes (approximately 60%).