Metatarsal metastasis from clear cell renal cell carcinoma: a case report and literature review

BACKGROUND: Bone metastasis is known to occur in some patients with cancer, usually in the spine, pelvis or ribs, and less than 0.01% of patients have metastases in the foot bone, so metatarsal metastasis is quite rare. The initial symptoms of osseous metastases are swelling, pain, or both. CASE PRESENTATION: We report a 68-year-old man with solitary metatarsal metastasis 26 months after a diagnosis of renal clear cell carcinoma. The patient suffered intermittent swelling of his right foot and pain for one year due to trauma and was not treated. The doctor attributed the symptoms to trauma, administering massage therapy and a plaster cast to the patient at the local clinic. After reviewing the medical records, we found that this patient had a history of clear cell renal cell carcinoma. The patient underwent radiological examination and open biopsy of the first metatarsal bone of the right foot. These findings confirmed that the patient had a metatarsal metastasis from clear cell renal cell carcinoma. The patient subsequently underwent right foot amputation. No local recurrence or distant metastasis was found after a 6-month follow-up. CONCLUSION: Clinicians should be aware of a history of renal cell carcinoma (RCC) and fully understand the patient’s past medical history. When treating patients with clear cell renal cell carcinoma who have unresolving bony pain or swelling, clinicians should always keep in mind the possibility of bone metastasis of RCC.