Role of Immunohistochemistry in Metastatic Bone Diseases

Objectives: To identify the role of immunohistochemistry in correctly identifying metastasis of bone disorders. Study Design: Cross-sectional study Place and Duration of Study: Department of Histopathology Pakistan Naval Ship, Shifa Hospital, Karachi Pakistan, from Jun 2019 to Jun 2020. Methodology: Patients aged 18-75 years, of either gender, already diagnosed case of the primary tumour, and now diagnosed with bone metastasis on biopsy were included. Various imaging techniques were used to locate the site of metastases. The histopathological reports of all the intra-operative specimens of bone metastases were reviewed. Results: The mean age of 60 patients was 59.5±28.8 years and mean weight was 67.4±13.5 kg. The period of presentation from diagnosis of the primary tumour was 34±15.4 months, and the period from onset of symptoms was 8.2±5.8 months. The most common site of the primary tumour was the breast in 18(30%) of patients, followed by the kidney in 14(23.3%) of patients. The most common site of metastasis was the femur in 30(50 %) of patients, followed by the spine in 15 patients. Conclusion: The most common site of primary tumour identified by immunohistochemistry was the breast, followed by the lungs. The femur was the most common site of metastasis, followed by the spine.