According to the most recent revision (2004) of the World Health Organization (WHO) histological classification system for<unk>  tumors ("WHO2004"), currently the most widely recognized typing scheme for pulmonary neoplasia, MCACL is considered a distinctive variant of adenocarcinoma. Informally, some experts have included these tumors as a distinct variant among a spectrum of mucus-producing adenocarcinomas, including — in order of increasing relative extent of cellular mucus production and extracellular mucus accumulation — solid adenocarcinoma, mucoepidermoid carcinoma,<unk>  bronchioloalveolar carcinoma, signet ring cell adenocarcinoma,<unk><unk> , and<unk>  "colloid" adenocarcinoma.
Mucinous cystadenocarcinoma of the lung
Epithelial-myoepithelial carcinoma of the lung
Atypical pulmonary carcinoid tumour
Salivary gland–like carcinoma of the lung
Large cell neuroendocrine carcinoma of the lung
Giant-cell carcinoma of the lung
Sarcomatoid carcinoma of the lung
Basaloid large cell carcinoma of the lung