Osteosarcoma relapse as pleural metastasis
A 14-year-old male patient with osteosarcoma of tibia received preoperative chemotherapy with cisplatin and doxorubicin. He had undergone mid-thigh amputation in November 2007. Histopathological examination from the lesion at the upper end of tibia was suggestive of osteogenic sarcoma. The patient then received 6 cycles of cisplatin and doxorubicin until June 2008. A computed tomography (CT) thorax done at that time revealed no abnormality. The patient presented to us in April 2012 with cough and pleuritic chest pain for the last 7 days. Clinical examination findings were suggestive of left-sided massive pleural effusion. Hematological examination showed normocytic, normochromic anemia (Hb 9.5 g/dl) with normal erythrocyte sedimentation rate. Pleural fluid was lymphocytic, exudative in nature with adenosine deaminase level 13.3 (normal <30 U/L). Pleural fluid cytology for malignant cells was negative on three successive occasions. Contrast-enhanced CT thorax revealed a large, heterogeneous, calcified mass (+277 H.U) at left upper and middle lobe extending to the hilum, partially encasing the left main pulmonary artery along with left-sided massive pleural effusion resulting in complete collapse consolidation of the left lung []. CT-guided fine needle aspiration cytology from the lung mass was inconclusive. Flexible bronchoscopy done after pleural aspiration revealed no other abnormality. Thoracoscopy revealed a lung metastasis in right upper and middle lobe exposed on the surface of visceral pleura. A tumor about 2 cm in diameter was found on the surface of parietal pleura. Lung tumor was resected and biopsy of the pleural mass was carried out. Both the sections showed tumor composed of polygonal and spindle-shaped cells with hyperchromatic nuclei. The tumor cells showed nuclear pleomorphism. Tumor giant cells with large hyperchromatic nuclei were present. The tumor cells showed osteoid formation. Extensive areas of the tumor exhibited chondroid differentiation along with mitotic figures. The features were compatible with metastatic osteogenic sarcoma []. The patient was administered three more cycles of chemotherapy consisting of cisplatin and doxorubicin and did not develop any cumulative toxicity post-chemotherapy, in spite of the same chemotherapy regimen pre-relapse and post-relapse.