A 66-year-old man underwent computed tomography-guided needle biopsy of a suspicious renal mass. Two months later he underwent partial nephrectomy. Histology revealed a 30-mm clear cell renal cell carcinoma, up to Fuhrman grade 3. An area of the capsule was interrupted, which corresponded to a hemorrhagic area on the cortical surface. Under microscopy, this area showed a tongue of tumor tissue protruding through the renal capsule. A tumor deposit was found in the perinephric fat. These features suggest that tumor seeding may have occurred during the needle biopsy.
Adipose Tissue/*pathology ; Aged ; Biopsy, Needle/*adverse effects ; Carcinoma, Renal Cell/*secondary/surgery ; Humans ; Image-Guided Biopsy/adverse effects ; Kidney/*pathology ; Kidney Neoplasms/*pathology/surgery ; Male ; *Neoplasm Seeding ; Soft Tissue Neoplasms/*secondary