GRANULAR-CELL TUMORS OF THE LOWER RESPIRATORY-TRACT

Granular cell tumours rarely involve the lower respiratory tract. We r eport eight cases surgically resected at our institution. There were f our females and four males, aged between 18 to 56 years (mean 40). One tumour associated with a peripheral lung adenocarcinoma was asymptoma tic. The other lesions presented with obstructive pneumonitis (3 cases ), haemoptysis (2), dyspnea (1) or cough (1). These tumours were trach eal (1) or bronchial (6) and one case was located in the lung parenchy ma, Four cases were multicentric with associated lesions located in a bronchus (2), the oesophagus (1) or a mediastinal lymph node (1). All tumours, with the largest diameter ranging from 0.5-4.5 cm, were histo logically invasive. The tumours were positive for S-100 protein, neuro n specific enolase, KP1 (CD68) and vimentin. No tumour expressed desmi n, keratin or p53 oncoprotein. Our study demonstrates that, in spite o f marked anatomical and clinical polymorphism, the rare granular cell tumours of the lower respiratory tract have a constant histological ap pearance. Our observations confirm that large tumours (> 8-10 mm) usua lly extend beyond the tracheo-bronchial cartilages and, therefore, onl y surgical treatment may avoid recurrence.