Background: Metastasis of soft tissue sarcoma most commonly occurs to the lungs. There are very few studies on histology of pulmonary metastatectomy and hardly any wherein the histology of the primary tumor has been compared with the metastasis.
Aims and objectives: To review histologically all metastatic sarcomas to lung and compare with the primary where available.
Materials and methods: Ninety-five patients with pulmonary metastases from sarcoma were analyzed histologically for type of sarcoma, chemotherapy-related changes, and changes in adjacent lung. Various clinical parameters like laterality, multiplicity, and interval between primary and metastasis were also studied.
Results: Osteosarcoma constituted half of the metastatic sarcomas (48 cases, 50.5%) followed by synovial sarcoma (16 cases, 16.8%) and high grade spindle cell sarcoma-NOS (10 cases, 10.5%). The histology of primary and the metastases was similar in 60% of cases of osteosarcoma.
Conclusions: Osteosarcoma is the commonest metastatic sarcoma to the lung. There is often a change to fibroblastic histology in patients of conventional osteosarcoma treated with chemotherapy.