Tetracycline will cause golden yellow fluorescence in which bone lesion?

• A. Osteoid osteoma
• B. Osteoblastoma
• C. Osteosarcoma
• D. Ewing sarcoma

Answer: (A)

Tetracycline labeling works because tetracycline binds to calcium in actively mineralizing bone and, under UV light, emits a golden-yellow fluorescence. This highlights areas of ongoing osteoblastic activity and new osteoid formation. In osteoid osteoma, there is a small nidus with vigorous osteoid production and osteoblastic activity, so the nidus takes up tetracycline and glows brightly. Other options either lack focal osteoid production (like Ewing sarcoma) or involve more diffuse or malignant osteoid patterns (osteosarcoma), or are larger lesions (osteoblastoma) where the fluorescence is less focal and characteristic. Thus, the golden-yellow fluorescence from tetracycline best corresponds to osteoid osteoma.