[Clinical types of thoracic cancer. Bronchiolo-alveolar carcinoma and adenocarcinoma with bronchioloalveolar features: a clinico-pathological spectrum].

Bronchioloalveolar carcinoma (BAC) is a primary pulmonary adenocarcinoma (ADC) arising in the cells of the terminal respiratory unit. Its restrictive definition adopted by the 1999 WHO pathological classification requires a complete surgical resection of the tumour to exclude any signs of invasion. Although stage IIIB and IV tumours were excluded from the strict WHO definition of BAC the first international workshop on this tumour in 2004 emphasised the clinico-pathological continuum that exists between BAC as defined by WHO and ADC with BAC features (ADC-BAC). BAC and ADC-BAC are distinguished from other non-small cell carcinomas by an increased incidence in women, non-smokers and Asians. The predominant spread through the airways explains the frequent presentation as diffuse or multifocal consolidation and death is more often due to bilateral pulmonary infiltration than extra-thoracic metastases. Progression is slower and the prognosis better than that of other ADC. Surgery offers the best treatment for localised disease. The high frequency of epidermal growth factor receptor (EGFR) expression and amplification and/or mutation of its gene, as well as the finding in some cases of a major response to EGFR tyrosine-kinase inhibitors, have lead to several therapeutic trials of these drugs. However, the place of chemotherapy has recently been reviewed.