The examination of histological and cytological specimens plays a pivotal role in the diagnosis and staging of lung cancer. This review aims to describe why the correct choice of specimen type may be important in optimising patient management. Tissue biopsies obtained for diagnosis provide specimens that are the most highly sensitive for the diagnosis of malignancy and cell typing. In addition, they provide sufficient material for further detailed studies, either at the time of diagnosis or subsequently during the patient’s management. Cytology specimens, in contrast, have generally lower sensitivities, are recognised to be prone to false positive errors and in many instances provide very limited material for detailed immunohistochemical studies. Cytology specimens will, however, have an increasingly important role in lung cancer staging with the development of minimally invasive endoscopic techniques for sampling mediastinal lymph nodes. Lymph node aspiration, either via the oesophagus or the bronchus, provides a highly sensitive method for the detection of metastatic carcinoma. Furthermore, this allows access to nodal groups not assessable by mediastinoscopy. In future, tissue biopsy for histological assessment should be seen as the ‘gold standard’ for primary diagnosis in lung cancer patients.
