Percutaneous Biopsy of Metastatic Bone Lesions Invisible on Conventional Computed Tomography

Early detection and histopathological diagnosis of bone lesions with suspected metastasis are crucial for planning treatment of cancer patients. We present computed tomography (CT) findings of three cases with bone metastases that were diagnosed by CT-guided biopsy. All three bone lesions were highly suspicious for metastasis on magnetic resonance (MR) and fluoro-deoxy-glucose-positron-emission-tomography-CT (FDG-PET-CT); although they were not visible on conventional CT. Hence, all the biopsies were performed with reference to MR and FDG-PET-CT imaging findings. As a result of histopathological examinations, all three lesions were diagnosed as metastases of primary cancers. Bone lesions with positive MR and FDG-PET-CT findings in patients with a primary known cancer may be metastasis although they are invisible on conventional CT. These lesions should be biopsied with reference to MR and PET-CT findings for treatments of cancer patients. Key Words: Bone, Metastasis, Computed tomography, PET scan, Biopsy.