We present a case of a 22-year-old man with history of allogenic renal transplantation on immunosuppression, who underwent F-FDG-PET/CT to characterize a lesion in the transplanted kidney on ultrasonogram and contrast-enhanced computed tomography imaging. PET/CT revealed FDG avid lesion in the transplanted kidney and mural thickening involving the distal ileum, ileocecal junction, and ileocolic lymph nodes. Subsequent histopathological examination from the renal lesion revealed renal cell carcinoma in the transplanted kidney. Additionally, endoscopic biopsy from the ileal thickening revealed granulomatous inflammation, suggesting tuberculosis, which was missed on both ultrasonogram and contrast-enhanced CT imaging.