PRIMARY OSTEOSARCOMA DISTAL FEMUR;

Incidence of pulmonary metastasis detected at the time of diagnosis.

Abstract

Objectives: 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. Study Design: Descriptive case series. Setting and Duration: Orthopaedic
Surgery Unit, Mardan Medical Complex Teaching hospital, Bacha Khan Medical College, Mardan, KPK, Pakistan from March 2011 to
September 2012. Methodology: 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.
RESULTS: 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. Conclusions: 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.