<prompt> Following is true about bronchial carcinoids -Highly radiosensitiveMetastasis commonCarcinoid syndrome does not manifestCommonly arise from terminal bronchioles  <response>: Ans. is c i.e., Carcinoid syndrome does not manifest Bronchial carcinoid o Most patients 40 years o Not related to smoking o Most tumors are confined to main stem bronchi and commonly project into lumen. Some tumors penetrate the bronchial wall to fan out in the peri-bronchial tissue producing the collar-button lesion. o Most bronchial carcinoids :Do not have secretory activity. Do not metastasize to distant sites follow a benign course for long periods. Are amenable to resection. o Most common presentation is intraluminal growth which can cause cough, hemoptysis, secondary infections, bronchiectasis, emphysema and atelectasis. o Though very rare, some bronchial carcinoids may also present : i Carcinoid syndrome due to release of vasoactive amines :- Flushing, diarrhea, cyanosis ii Symptoms due to metastasis. 