A 5year-old child complains of pain and swelling of the right tibia. On laboratory evaluation he has elevated ESR and leucocytosis X-ray shows a tibial lesion. Which of the following is the best investigation which can help us clinch the diagnosis:

Diagnostic is always Tissue Diagnosis -Tumors and infection can mimic each other (clinically and radiologically), e.g. Osteosarcoma and Ewings sarcoma are two tumors that mimic osteomyelitis. (Both have accompanying fever and increased local temperature). -Tumors and bone infections are usually metaphyseal and both need tissue diagnosis for differentiation. Thus, Culture is gold standard for infection -Histopathology is gold standard for tumors So rule is Culture all biopsies, biopsy all cultures.