[Roundish opacity of the right lung (a clinical case)].

The authors describe a rare case of pulmonary hamartomyxoma observed by them as a secluded roundish opacity (coin lesion) in the middle right thoracic region. After reporting an accurate anatomic-radiology can description of the lesion, they expose the histogenesis and the classification attempts concerning the chapter about "hamartomas" through an ample revision of the cases reported in the last years.