MUC5AC and mucoepidermoid carcinoma: Mucin-producing adenocarcinomas of the lung can be differentiated into SRCC, solid adenocarcinomas with mucin production (SA), mucinous bronchioloalveolar carcinomas, mucinous (“colloid”) adenocarcinomas, mucinous cystadenocarcinomas, and mucoepidermoid carcinomas [10].