Unusual primary pleural leiomyoma

Primary pleural leiomyoma is extremely rare and has only been described a few times. We present a case of a young woman with right pleuritic pain. A computed tomography confirmed the existence of a solid right pleural tumor which had compressed and displaced the lung, mediastinum and heart. Percutaneous biopsy showed a 'proliferation of smooth muscle cells without evidence of malignancy'. Surgical excision was done and the tumor was not associated to vascular, broncho-pulmonary or mediastinal structures. The definitive diagnosis was primary pleural leiomyoma. Primary pleural leiomyoma should be included in a differential diagnosis of pleural tumors and suspected in asymptomatic patients with radiologically-apparent benign tumors and the presence of smooth muscle fibers in the biopsy. Complete resection and follow-up is advised because it can grow very large and has malignant potential.