“…GOOD, MCDONALD, CLAGETT & GRIFFITH (1950) presented the results of operation in 8 patients; one was alive and symptom-free two years after wards. Of 9 operated patients reported by SMITH, KNUDTSON & WATSON (1949), two were alive and free from recurrence five years after operation, which consisted in segmental resection and lobectomy, respectively; in each case the histological examination proved the condition to be benign.…”