Bone malignancies in orthopaedic hospital Igbobi Lagos, Nigeria

To document the pattern of bone malignancies in a highly populated orthopaedic hospital in Lagos Nigeria;

A total of 21 cases of primary malignant bone tumours were studied. This comprised 12 cases of Osteosarcoma, 7 cases of Malignant Fibrous Histiocytoma (MFH) and 2 cases of Chondrosarcoma. Males (13) were affected more than females (8) giving a male to female ratio of 1.6 to 1. The age range was 7 to 45 years with a median age of 24 years. The diameter of the swelling ranged from 6 to 20 cm with a median of 12 cm. All patients had ablative surgery except for those with affectation of the ilium. Data was analysed using the Statistical Package for Social Sciences (SPSS 16). Enneking's classification was used to grade the tumour. The duration of symptoms of all the patients before presentation ranged from 3 weeks to 4 years with a mean of 7 months. The commonest site affected was around the knee (76.2%); distal femur had 42.9% and proximal tibia 33.3%.

Osteosarcoma was the most common malignant bone tumour in this series and accounted for 57.1%. The peak incidence was found in the 2nd decade of life. The youngest patient was 7 years old and the oldest 43 years. The tumour was found primarily around the knee. 7 cases were in the distal part of the femur, 4 in the proximal part of the tibia and 1 case was found in the distal radius. Out of the 12 patients with osteosarcoma, 8 had paraosteal type (5 high grade, 3 intermediate grade), the remaining 4 had periosteal (all high grade) Malignant Fibrous Histiocytoma was found in 7 patients and accounted for 33.3%. The peak incidence was found in 3rd and 4th decades. 4 out of the 7 patients were high grade pleomorphic osteosarcoma, 2 were myxoid high grade dedifferentiated and one was low grade giant cell tumour type. Chondrosarcoma was found in 2 patients, accounting for 9.5%. both cases were in the ilium

Primary malignant bone tumours occurred in children and young adult in this study. It is commoner among males and most of the patients presented late to the hospital. Osteosarcoma is the commonest followed by Malignant Fibrous Histiocytoma, both occurred commonly around the knee and chondrosarcoma on the ilium.