Prostate cancer bone metastases confined to the distal left lower limb

Bone metastases from prostate cancer most commonly affect the axial and proximal appendicular skeleton with rare involvement of the distal limbs. We describe a case of multiple bone metastases confined to the left lower limb in a patient with biochemical recurrence of prostate cancer. Following an initial post-operative PSA rise, the patient received a course of salvage radiotherapy to the pelvis, however, the PSA level continued to rise and two consequent staging CT scans were negative for local recurrence and metastatic disease. Subsequent development of left ankle pain and swelling led the patient to present to his General Practitioner, which triggered a series of imaging investigations that revealed isolated left lower limb bone metastases. This case report highlights the need to consider peripheral limb bone metastases in patients with biochemical recurrence of prostate cancer, particularly in the setting of a negative staging CT scan and/or bone pain.