Prolonged remission of disseminated atypical adenomatous hyperplasia under gefitinib.

Atypical adenomatous hyperplasia (AAH) is a putative precursor of bronchioloalveolar carcinoma (BAC) and adenocarcinoma of the lung, developing from terminal respiratory unit cells. AAH and BAC lesions typically present as ground-glass opacities at spiral chest computed tomography. Epidermal growth factor receptor polysomy/mutations, conferring higher sensitivity to Gefitinib, are frequent in BAC but less common in AAH. We describe an interesting case of disseminated AAH showing a sustained remission under Gefitinib therapy.