<prompt> About lung metastasis, which is true?Associated with cough with sputum productionBilateral and multipleNormal chest X-raySingle lesion  <response>: Ans: b Bilateral and multiple Ref: Davidson, 20th ed,p. 711SECONDARY TUMOURS OF THE LUNGBlood-borne metastatic deposits in the lungs may be derived from many primary tumours. The secondary deposits are usually multiple and bilateral. Often there are no respiratory symptoms and the diagnosis is made by radiological examination. Breathlessness may occur if a considerable amount of lung tissue has been replaced by metastatic tumour. Endobronchial deposits are uncommon but can cause haemoptysis and lobar collapseCOMMON CELL TYPES OF BRONCHIAL CARCINOMA HarrisonCell typeAdenocarcinoma32Squamous29Small-cell18Large-cell9This Table is given in Harrison pg 506, the values in Davidson are differenetCOMMON CELL TYPES OF BRONCHIAL CARCINOMA DavidsonCell typeSquamous35Adenocarcinoma30Small-cell20Large-cell15Note:Small cell carcinomas are very notorious and they usually have already spread at the time of presentation such that surgery is unlikely to be curative, and they are managed primarily by chemotherapy with or without radiotherapy.The most common form of lung cancer arising in lifetime non-smokers, in women, and in young patients 45 years is adenocarcinoma.Squamous and small cell cancers usually present with endobronchial growth, while adenocarcinomas and large cell cancers tend to present as peripheral nodules or masses, frequently with pleural involvement.Squamous and large cell cancers cavitate in 10-20 of casesBronchoalveolar carcinoma, a form of adenocarcinoma arsisng from peripheral airways, can present radiographically as a single mass; as a diffuse, multinodular lesion; or as a fluffy infiltrateAdrenal metastasis is common in lung cancer but rarely cause adrenal insufficiencyClubbing and hypertrophic pulmonary osteoarthropathy are more common in adenocarcinomas. 