Bronchioloalveolar adenocarcinoma with myoepithelial cells

A unique variant of papillary lung carcinoma in a 58-year-old woman with both Clara cell and myoepithelial components is reported. The tumor was characterized by the presence of glandular spaces lined by two cell layers. The superficial (luminal) layer was made up of columnar cells with ultrastructural and immunohistochemical features of Clara cells, and occasional interspersed type 2 pneumocytes. The cells of the basal layer possessed ultrastructural and immunohistochemical features of myoepithelial cells. Myoepithelial cells have not previously been reported in a bronchioloalveolar adenocarcinoma.