Benign pleural lesions simulating tumour.

Without the aid of thoracotomy it is often difficult to establish a diagnosis in cases of tumour in the thorax. Certain forms of benign pleural changes are likely to be misinterpreted as intrapulmonary, and operation for suspected lung tumour may be carried out. In the cases described here, it was possible to establish the diagnosis without employing thoracotomy. As very little attention appears to have been paid to these lesions in the literature, a number of cases recently observed have been collected.