BAC pattern

BAC pattern

Bronchioloalveolar carcinoma pattern. A term of art referring to a so-called lepidic (hobnail-like cells spreading across a surface) growth pattern of a tumour that mimics classic bronchioloalveolar carcinoma.
References in periodicals archive ?
59) Nevertheless, radiologic-pathologic correlation studies suggest that a radiographic GGO pattern from an adenocarcinoma corresponds to a histologic BAC pattern, whereas radiographic solid components indicate the presence of a histologic invasive component.
19) The same excellent survival that is observed in cases with pure BAC tumors is seen even for tumors with questionable single-cell invasion, as well as minimal stromal invasion in areas of BAC pattern (Figure 6) or at the edges of fibrotic areas.
In small adenocarcinomas with definitive invasion, those tumors with minimal or with no BAC-like component were found to be more aggressive than those classified as mixed BAC pattern (at least 10% lepidic growth pattern).