The role of whole-body bone scan in a rare case of colon cancer with lesions potentially mistaken for bone metastases but diagnosed as bony lesions of osteopetrosis.

Background: Bone metastases are complications of many cancers, including colon cancer. Whole body bone scan is commonly used to detect bone metastases in these patients. Bone scan findings are sensitive for detecting metastases but with less experience and especially without the use of single photon emission computed tomography/computed tomography (SPECT/CT) images, they are less specific. This means that while bone scans are effective at identifying areas of abnormal bone activity, they may not always distinguish between bone metastases and other conditions, such as fractures, infections, or benign bone diseases such as a rare condition like osteopetrosis, leading to potential false positives. This 52-year-old male patient was referred for a whole-body bone scan for evaluation of bone metastasis. At first glance, the scan pattern with multiple foci of increased radiotracer uptake seemed to indicate bone metastases due to the patient's colon cancer. However, upon closer inspection of the bone scan and careful attention to details such as bone deformities and cortical thickening, along with obtaining a more detailed patient history and reviewing other radiological records, the diagnosis of osteopetrosis was made.

Conclusions: This case demonstrates the importance of carefully interpreting bone scan findings when diagnosing metastasis. It highlights that other benign diseases, including rare conditions such as osteopetrosis, can mimic the appearance of bone metastases on scans. Therefore, it is crucial to pay close attention to any abnormal patterns, like cortical thickening and bone deformity, and to thoroughly review the patient's medical history and other relevant clinical data and imaging findings. This comprehensive approach helps avoid misdiagnosis and ensures accurate interpretation of the scan results.