Resected sigmoid carcinoma with 13-year metastasis-free interval. Sternal recurrence detected by immunoscintigraphy.

Colorectal cancers rarely present with bone metastases. Regular postoperative monitoring after resection by conventional imaging techniques and carcinoembryonic antigen levels aids physicians in identifying such tumor recurrences. However, some recurrences might elude detection by bone scan, computed tomography, and magnetic resonance imaging, and newer tests such as immunoscintigraphy using radioimmune-tagged monoclonal antibodies may be more diagnostic. Here we report a case, presenting with delayed recurrence at a rare bony site, in which application of immunoscintigraphy helped in the definitive detection of the tumor recurrence.