Solitary metastases of colon adenocarcinoma to the ankle: A case report and literature review.

Introduction: Colorectal cancer (CRC) is a major cause of cancer-related mortality, with metastases typically involving the liver and lungs. Solitary bone metastasis to the ankle is exceedingly rare and presents significant diagnostic challenges.

Case Presentation: A 46-year-old male presented with constipation, abdominal pain, and persistent right foot discomfort following a previous talus fracture that failed to heal with conservative management. Imaging studies revealed a sigmoid colon mass and a Solitary lesion in the right talus. Biopsy of the colon and ankle specimens confirmed poorly differentiated signet ring cell adenocarcinoma. The patient was treated with a chemotherapy regimen and palliative radiotherapy which led to improved performance status.

Clinical Discussion: Colon and rectum have different patterns of metastasis due to different vasculature and anatomy. Although metastatic bone lesions can be seen in both of them, talus bone involvement has been rarely reported. Non-specific skeletal-related events should be taken into consideration as they can be primary symptoms of bone metastasis or even the first symptoms that lead to CRC diagnosis.

Conclusion: This case highlights a rare solitary metastatic pathway of CRC and underscores the importance of a comprehensive diagnostic work-up in patients with treatment-refractory bone disorders.