MUC5AC and microscopic polyangiitis: By histological analyses [10], 41 patients were acinar predominant adenocarcinoma (APA), 20 were papillary predominant adenocarcinoma (PPA), 25 were solid predominant adenocarcinoma (SPA) with mucin production, 15 were other types including lepidic predominant adenocarcinoma (LPA), micropapillary predominant adenocarcinoma (MPA) and adenosquamous carcinoma.