PMC4900125_01
23-year-old male with extraosseous pulmonary Ewing sarcoma. Initial presentation. (A) Chest x-ray demonstrates partial opacification of the right hemithorax; a triangular, dense opacity in the mid-lung extends from the right hilum to the chest wall. (B) A noncontrast chest CT at the level of the right mainstem bronchus demonstrates a large, slightly hypodense soft-tissue mass in the right upper lung with internal foci of hyperattenuation representing calcifications. The mass abuts, but does not invade, the pleural space and chest wall. Note the absence of adjacent osseous destruction. However, the mass does insinuate within the mediastinum, with significant mass effect on the right mainstem bronchus, which is nearly completely occluded. Small ipsilateral effusion was also present, though not demonstrated in this image. (C) PET/CT confirms the presence of an FDG-avid mass in the right mid-lung invading the right upper mediastinum, with no additional foci of radiotracer uptake to suggest metastatic disease.
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A chest radiograph was eventually obtained (Fig 1A). A noncontrast CT of the chest was subsequently performed (Fig. 1B). PET/CT confirmed a metabolically active mass (SUV = 14.7) in the right hemithorax within the lung parenchyma, with no additional foci of increased radiotracer activity to suggest metastatic disease (Fig. 1C).
23-year-old male with extraosseous pulmonary Ewing sarcoma. Pathology of the tumor. A. A nodular, focally necrotic, and calcified tumor wtihin the right upper lobe. B. Nests of tumor cells infiltrate the subepithelial space of a bronchus (H&E, X10). C. Higher manigification shows primitive small-to-medium cells with focally increased mitotic figures (x400). D. Characteristic CD99 immunoreactivity of the cell membranes (x400).
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Review of the final pathology of the original biopsy specimen at our institution demonstrated densely packed neoplastic cells in a background of fibromyxoid stroma with patchy hemorrhage, fibrosis, and geographic necrosis (Fig. 2).
23-year-old male with extraosseous pulmonary Ewing sarcoma. Post-therapy. (A) During pre-operative chemotherapy, contrast-enhanced chest CT was obtained. Image at the level of the carina demonstrates significant interval reduction in size of the mass. The right mainstem bronchus is no longer occluded, though it remains narrowed. Subsequently, surgical resection was performed, and followup contrast-enhanced CT was performed 3 months postoperatively. (B) Contrast-enhanced CT after surgery demonstrates no evidence of residual disease. Mild irregularity along the posterior wall of the right mainstem bronchus suggests granulation tissue at the surgical site; the right mainstem bronchus is otherwise widely patent.
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After six cycles of chemotherapy, there was significant decrease in size of the mass (Fig. 3A), and the patient underwent right upper lobectomy, right mainstem bronchus resection, right sixth rib resection, and mediastinal tumor resection. It has now been six months since initial diagnosis, and followup CT imaging demonstrates post-surgical changes with no evidence of disease recurrence (Fig. 3B).