<unk>  cell lung cancer is often treated as a systematic disease due to its tendency for early dissemination, thus, instead of the traditional TNM<unk> ng system, the Veterans' Administration Lung Study Group (VALSG) introduced a simplified 2-stage system in 1950s to divide<unk>  cell lung cancer into<unk><unk>  and extensive<unk> . As a result of the change in policy from targeting all nodal stations by radiotherapy ports to target only obviously involved nodal stations, the definition of the<unk>  disease varies. According to a broad medical consensus,<unk>  is generally considered to be encompassed within a radiation portal. Variability in categorising<unk> -cell lung cancer as<unk>  or extensive occurs with reference to the extent of pleural effusion and nodal stations involvement. In addition, patients with an ipsilateral pleural effusion are frequently excluded from the<unk> -disease category. In rare cases, patients with minimal pleural effusions are included in the<unk> -disease protocols; this includes those with demonstrated effusions only on chest CT, as well as those with blunting of the costophrenic angle on chest radiographs. In most cases, all patients demonstrated any positive sign of pleural effusion on any type of imaging tests are excluded. Likewise, ambiguities in the definition of<unk>  disease also occurs in classification of the<unk>  disease with reference to the extent of lymphadenopathy. For instance, patients with bilateral supraclavicular adenopathy are included in the<unk> -disease category in some cases, others include only those with ipsilateral adenopathy. Similarly, the presence of contralateral hilar adenopathy frequently, though not uniformly, includes patients in the<unk> -disease category. The traditional TNM classification system is preferred over the 2-stage system when surgery is the recommended treatment option.
Limited-stage small cell lung carcinoma
Minimally invasive adenocarcinoma of the lung
Salivary gland–like carcinoma of the lung
EML4-ALK positive lung cancer
Combined small-cell lung carcinoma
Atypical pulmonary carcinoid tumour
Epithelial-myoepithelial carcinoma of the lung
Large cell neuroendocrine carcinoma of the lung