ABSTRACT
The current case study had described the clinical presentation, evaluation, management, and outcome of a case of primary Ewing's Sarcoma of the lung. It was presented with cough, chest pain, and hemoptysis for 3 months in a 36-year-old male. Immunostaining of the sections prepared from the blocks using CD99 antibody revealed strong continuous cell membrane staining. Tumor cells showed negative staining for leukocyte common antigen (LCA), thyroid transcription factor 1 (TTF1), and pan-cytokeratin (AE1/AE3) consistent with extraskeletal Ewing's sarcoma (EES). Neoadjuvant chemotherapy of 6 cycles followed left lower lobectomy had led to good recovery and the patients are disease free at 18-month follow-up. Primary EES of the lung should be considered in the differential diagnosis when a young patient is presented with large mass without evidence of primary extrathoracic disease.