Abscopal effect in a biopsy-proven chromophobe renal cell carcinoma before planned cryoablation

The abscopal effect, defined as regression of untreated tumors following localized therapy, is rare in renal cell carcinoma (RCC). We present a case of a 49-year-old male who was incidentally found to have a 1.2 cm enhancing mass in the medial lower pole of the left kidney. MRI confirmed a small solid neoplasm, and percutaneous biopsy confirmed histopathological chromophobe RCC diagnosis. The patient was scheduled for cryoablation. On pre-procedural multiphasic CT, the lesion had completely regressed, leaving only a 6 mm cortical scar without enhancement. Cryoablation was aborted, and the patient was placed on active surveillance. This case illustrates the abscopal effect in primary RCC, likely triggered by biopsy as the inciting local event. Recognition of this rare immune-mediated phenomenon emphasizes the importance of confirmatory imaging before intervention and highlights the evolving interplay between radiology, minimally invasive procedures, and tumor immunology.