Histopathological pattern of primary bone tumours at the Black Lion Specialized Hospital, Addis Ababa, Ethiopia: a retrospective cross-sectional, 2015-2019.

Introduction: there is few data on epidemiology or clinico-pathology of primary bone tumours in Ethiopia. Bone tumors often have a similar presentation and clinical approach, but they present individual characteristics that are important for treatment and prognosis. This study aimed to provide a brief overview of histopathological pattern of primary bone tumours and the distribution of specific diagnosis by age, sex and anatomic locations. Methods: a retrospective descriptive cross-sectional study was conducted from January 2015 to October 2019 in the Department of Pathology, College of Health Sciences, Addis Ababa University based on surgical biopsy results. Results: there were 335 patients; 158 (47%) had benign tumours and 177 (53%) had malignant tumours. Osteochondroma was the most common benign bone tumour with 32.3% followed by giant cell tumour 16.5%, chondroma 11% and others 40.2%. Osteosarcoma constitutes 62% of all primary malignant bone neoplasms, followed by ewing sarcoma 15.2%, chondrosarcoma 11.3%, and others 11.5%. Most age group affected by primary bone tumours were 10-29 yrs and most common locations of presentation for primary malignant bone tumours were distal femur and proximal tibia. Conclusion: the present study results parallel the findings previously reported in literature and show a similar distribution of primary bone tumors as in the other developed and underdeveloped countries.