[Differential diagnosis between peripheral lung cancer invading the chest wall and chest-wall tumors].

Preoperative histological diagnosis of lung cancer is usually based on findings from a transbronchial biopsy specimen of the tumor obtained through a fiberoptic bronchoscope. However, peripheral pulmonary tumors can be difficult to diagnose in this way. We report two patients with lung cancer invading the chest wall for whom histological diagnoses were not possible by transbronchial biopsy. Treatment for lung cancer is different from that for chest-wall tumors, so preoperative differential diagnosis of these conditions is important. Other organs should be searched to exclude metastatic chest-wall tumors. Percutaneous needle biopsy done under ultrasonic guidance made the histological diagnosis of lung cancer possible in both cases.