Role of 18F-FDG PET/CT in the diagnostic work-up of renal cell carcinoma presenting as low back pain

ABSTRACT

@#Low back pain is common among adults, but back pain secondary to a metastatic carcinoma is rare. We present a case of a 71-year-old male with low back pain who was referred for a 18F-FDG PET/CT scan due to suspicious-looking skeletal lesions on MRI. On PET/CT, multiple foci of increased FDG uptake were noted in the axial and appendicular skeleton. When correlated with a non-contrast CT stonogram done 2 months prior, an exophytic lesion in the right kidney did not show FDG update; rather, it was in the left kidney where an FDG-avid focus was seen. A concomitant bone scan revealed fewer bone lesions when compared with the PET/CT findings. Biopsies of the left renal mass and a vertebral lession were consistent with metastatic renal cell carcinoma. While not a first-line diagnostic test in the management of low back pain, 18F-FDG PET/CT scan can be valuable in cases where metasis highly suspected without a known primary carcinoma site.