2010 Volume 46 Issue 1 Pages 48-52
We report a case of cellular-type mesoblastic nephroma (MN). A 3-month-old boy was admitted to our hospital because of sucking loss and a huge abdominal mass 12 centimeters in diameter. The cut surface was milk-white and solid; we had difficulty in a differential diagnosis between a Wilms tumor and clear cell sarcoma of the kidney. In pathologic findings, the tumor was composed of elongated spindle cells forming dense fascicles, and a specific ETV6-NTRK3 fusion-gene product was detected by RT-PCR; therefore we diagnosed cellular-type mesoblastic nephroma. The tumor was completely excised, and the patient has been well and free of tumor for a year after surgery.
