Adenocarcinoma is classified under non-small cell lung cancer (NSCLC) because of its histological characteristics—specifically, it arises from glandular epithelial cells and typically shows features such as gland formation or mucin production. NSCLC is a broad category that includes tumors with these types of differentiated structures, distinguishing them from more primitive or neuroendocrine cell types. Adenocarcinoma, along with squamous cell carcinoma and large cell carcinoma, fits within this group because its cellular architecture is consistent with epithelial origin and does not display the defining traits of small cell tumors.
In contrast, small cell lung cancer (SCLC) is composed of poorly differentiated neuroendocrine cells that are smaller in size, have minimal cytoplasm, and exhibit rapid growth and early metastasis. These tumors lack the glandular differentiation seen in adenocarcinoma and behave very differently both biologically and clinically.
Cancer: Lung, Non-Small Cell: 0.07, 0.12, 0.6, 0.8, 2.5, 22.5, 72.5, 434.39, 739.1, 905.31
