Cerebellar metastasis from clear cell sarcoma of the kidney. A case report with immunohistochemistry

The aim of this study was to describe a child with a right cerebellar hemisphere metastasis from primary clear cell sarcoma of the kidney without evidence of bone metastases, and to investigate the immunohistochemical features of primary and metastatic tumors. A 12-month old boy was admitted our hospital due to an abdominal mass. Abdominal computed tomography revealed a large right renal tumor. Tumor was removed with nephrectomy. Histopathologic examination of tumor revealed clear cell sarcoma of the kidney. The patient received radiotherapy and chemotherapy in postoperative period. He suffered from gait disturbance and confusion 8 months later. A computed tomography scan revealed a tumor that was enhanced with contrast medium at right cerebellar hemisphere concomitant with ventricular enlargement. After ventriculo-peritoneal shunting procedure, tumor was excised totally and histopathologic diagnosis showed metastasis of clear cell sarcoma of the kidney. Immunohistochemically vimentin, actin, desmin, neuron specific enolase, cytokeratin, P 53, Ki-67 and P-170 were performed using formalin fixed, paraffin embedded sections. Both of the tumors were positive for vimentin and negative for desmin, actin, neuron specific enolase, cytokeratin and P 53. Scattered nuclei were stained by Ki-67 in primary and metastatic cerebellar tumor. Both primary and metastatic tumors were negative for p53 and P-170. The treatment consisted of surgery, radiotherapy and chemotherapy. The patient is alive and well without evidence of recurrence 16 months after second surgery. Clear cell sarcoma of the kidney is most commonly associated with bone metastasis. Cerebellar metastasis of clear cell sarcoma of the kidney is very unusual. To the best of our knowledge, this patient is second case in the English literature. With review of the literature, our immunohistochemical findings support the theory that relapse and metastasis of primary clear cell sarcoma of the kidney are not related with increase of aggressiveness.