Clinicopathological study of Atypical Adenomatous Hyperplasia of the Lung

We report a retrospective clinicopathological review of our experience with surgically excised atypical adenomatous hyperplasia (AAH). Between June 1999 and May 2002, 17 patients underwent surgical resection of AAH. There were 5 males and 12 females with a mean age of 64 years (range 44-83 years). The size of the tumor excised ranged from 4 to 20mm on HRCT (mean 9.2mm). Tumors≥5mm were present in 14 of 18 (77.8%) cases and in 8 of 18 (44.4%) of the cases the tumor was in fact≥10mm in diameter. In 2 patients there was no evidence of pure ground glass opacity. Single AAH was found in 15 patients, multiple AAH were seen in 1 patient and in 1 patient AAH was seen concomitantly with bronchioloalveolar carcinoma. This report is unique in that it describes outcome for AAH in isolation from primary lung cancer. It is likely that with mass screening programs with CT in the near future there will be increasing numbers of patients with isolated AAH. We believe that it is likely to be beneficial to identify these patients and offer minimal surgical resection of these lesions as it will have an impact on the activities of daily living and quality of life in these patients.