ABSTRACT
This study was designed to estimate the incidence rate of pulmonary metastasis at the time of diagnosis of primary osteosarcoma distal femur in a tertiary care hospital. Descriptive case series. Orthopaedic Surgery Unit, Mardan Medical Complex Teaching hospital, Bacha Khan Medical College, Mardan, KPK, Pakistan from March 2011 to September 2012. Nine patients of primary osteosarcoma distal femur were assessed with CT chest for pulmonary metastasis. The frequency and patterns of pulmonary metastasis on CT chest were documented. After the biopsy reports all patients were referred for neo adjuvant chemotherapy before any definite surgical procedure. The histological types of osteosarcoma were noted. Nine patients including 7 male [77.7%] and 2 females [22.2%] with mean age 12.4 years were included in our study. 66.6% [n=6, 5 males, 1 female] had pulmonary metastasis on CT chest at initial presentation while 33% [n=3,2 males,1 female] had no pulmonary metastases on CT chest. Three [50%] patients had pulmonary metastasis in the right lung, 1[16.6%] had on left side while 2[33.3%] had bilateral pulmonary involvement. Of the cases with metastases at diagnosis, 55.5% had osteoblastic histology of osteosarcoma compared with 33.3% of those with non metastatic disease. Majority of osteosarcoma distal femur presented with pulmonary metastasis at initial presentation. A high index of suspicion accompanied by careful examination of the limb and appropriate radiographs at initial assessment may reduce the incidence of such delays in diagnosis and the associated risks