BAC is a histological subtype of non-small cell lung cancer (NSCLC) that is known to have a distinct presentation and natural history. The 1999 WHO classification of BAC is more restrictive by excluding stromal, vascular and pleural invasion. Our purpose was to investigate the natural history, demographics and survival outcomes for a cohort of patients registered with BAC prior to 1999. Our intent was to determine if a more restrictive cohort of BAC resulted in a survival advantage. Additionally, our intent was to hypothesize subsets that may have maximal benefit from epidermal growth factor (EGFR) inhibitors, which have documented activity in BAC. The records from the Tumor Registry of ScottsWhite Hospital were retrospectively reviewed for all BAC cases from 1986–1998. There were 100 cases eligible for review. Demographic data and information on clinical presentation was collected through both chart reviews and tumor registry abstracts. All cases were pathologically reevaluated using the revised WHO system. Kaplan-Meier product-limit survival curves were computed and compared for the true BAC (classic) and adenocarcinoma with BAC features (non-classic) groups. Gender, smoking history, presenting complaint, type of surgery, stage and treatment modalities were compared for both subgroups. Of the entire group 55% were male, 78% were smokers and the presenting complaint in 71% of the cohort was an asymptomatic chest x-ray. There were no significant differences between the classic and non-classic groups for these factors. The cumulative survival curves for the classic and non-classic designation were not significantly different (p = 0.44) with a median survival for the classic group of 4.6 years versus 3.2 years for the non-classic group. Among the 100 cases 30% were reclassified as true BAC and 33% of these were mucinous. Of the group 23% were stage IV at presentation and, of note, chemotherapy was used in 6% of the patients. Radiation therapy was used as part of primary treatment in 13% of the patients. The literature on the natural history of BAC needs to be reevaluated given the revised WHO classification. Our data does not discriminate clinical outcomes for classic BAC and adenocarcinoma with BAC features. Our data supports a trend toward under treatment in a group of patients with a median survival of 3.5 years. There was a non-significant trend toward an improved survival for classic mucinous (6.3 years) versus classic non-mucinous (4.0 years) BAC. This finding supports data that non-mucinous BAC has higher expression of EGFR