Prevalence of malignancy in preoperatively undetermined solid round lesions

: We report on 20 patients submitted to surgery, with an average age of 53.9 years (+/- 8.8), in whom solitary pulmonary nodules were not amenable to preoperative diagnosis on the basis of biopsy material. It was shown that 35 per cent of the unclear solitary lesions were malignant. Provided that the medical risks of surgery can be justified, surgical clarification via a thoracotomy in patients in this age group is indicated.