Pulmonary Blastoma that was first diagnosed as dedifferentiated chondrosarcoma using Medical Thoracoscopy: A case report
TH. Kima (Dr), JH. Jeonb (Prof), JH. Chungc (Prof), YJ. Cho*a (Prof)
a Divisions of Pulmonary and Critical Care Medicine, Department of Internal medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, KOREA, REPUBLIC OF ; b Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, KOREA, REPUBLIC OF ; c Department of Pathology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, KOREA, REPUBLIC OF
Pulmonary blastoma is a rare and highly aggressive malignancy, constituting about 0.5% of all lung tumors. The tumor is composed of low-grade fetal adenocarcinoma and primitive mesenchymal cells showing various degrees of differentiation.
We report a 65-year-old man with 1 pack per day of smoking for 15 years. The patient complained of mild dyspnea and right-side chest discomfort and a chest X-ray showed right-side pleural effusion. Diagnostic thoracentesis was performed but the result was exudate nature but inconclusive (polymorpho-nuclear cell 12%, mononuclear cell 88%, ADA 19 IU/L, negative for malignant cells in cytology). Medical thoracoscopy (MT) was performed for the final diagnosis. All the pleural space was multi-septated, and severe adhesion in the pleura space was observed including a whitish mass-like lesion between the lung basal and the pleura. Multiple biopsies were done from the involved pleura and the mass. There was no endobronchial tumorous lesion in bronchoscopy. According to the pathological results, the pleura tissue showed granulation tissue without malignancy, and the white mass was diagnosed as dedifferentiated chondrosarcoma (positive for S-100 and CD99, negative for CD 34, calretinin, STAT6, D2-40).
After a multidisciplinary discussion, the patient was treated with exploratory video assisted thoracoscopic surgery. Much pleura area was dissected and a huge mass of the right lower lung was observed during surgery. Bilobectomy including decortification was performed finally. The final pathology was confirmed as pulmonary blastoma [primitive mesenchymal area (40%), chondrosarcoma (50%), adenocarcinoma (5%), and osteosarcoma (5%)], and pleural metastasis was confirmed. Additional chemotherapy is being administered.
MT is useful for the diagnosis of indeterminate pleural effusion, however, cautions are also needed when confirming rare malignancy such as pulmonary blastoma.
Disclosure of funding source(s): none