RESUMEN
Splenosis refers to the heterotropic autotransplantation of splenic tissue. Sometimes splenosis after surgical resection is difficult to differentiate from recurrence or metastasis of cancer. A 49-year-old male patient was diagnosed with clear cell renal cell carcinoma of left kidney. As there was no evidence of metastasis, he underwent radical nephrectomy with splenectomy. On surveillance computed tomography, masses at nephrectomy site and pleura were found and both were initially considered to be recurrence. After several cycle of pazopanib administration, pleural mass decreased in size while mass at nephrectomy site did not respond at all. Spleen scan showed increased uptake of the mass and therefore the mass was revealed to be splenosis. To avoid unnecessary treatment and planning optimal treatment, considering the possibility of splenosis is important and spleen scan can be helpful.