Solitary Metastatic Lesion of the Tibia from Clear Cell Renal Carcinoma: A Case Report of Segmental Skeletal Resection, Intercalary Allograft Over Reamed Nailing and Soleus Flap Interposition.

BACKGROUND Renal cell carcinoma (RCC) is the most common malignancy of the kidney, with clear cell (ccRCC) subtype identified in 85% of the cases; one-third of these patients experience synchronous metastatic disease, while 20-30% of the remaining patients develop metachronous metastatic RCC. The axial skeleton (pelvis and sacrum) is the second most common location (following the lungs), with a reported incidence of 35%. Diaphysis of the long bones is rarely involved, with the tibia being an even rarer site of metastasis. CASE REPORT We present a rare case of solitary diaphyseal tibial metachronous metastasis from RCC in a 54-year-old male that appeared 8 years after nephrectomy without any previous evidence of disease. He underwent segmental skeletal resection, intercalary allograft over locked reamed intramedullary nailing, and soleus flap coverage. Thirty months later he presented with hardware failure and nonunion at the distal part of the allograft site. He was successfully treated with exchange nailing, fibular osteotomy, and bone grafting, showing excellent clinical and radiological outcome without any evidence of recurrence 5 years after the index operation. CONCLUSIONS Wide resection and biological reconstruction using intramedullary nailing and incorporated allograft is a good option for metachronous solitary RCC tumors.