Medical Health Encyclopedia

Until recently, adenocarcinoma was only weakly linked to smoking. Experts now suggest, however, that the dramatic increase over the past decades in this lung cancer type may be due to low-tar, filtered cigarettes. People who smoke them draw tiny particles deeper into the lungs, thereby possibly increasing the risk for adenocarcinoma.

The course of this cancer varies widely. Most often, it develops slowly and causes no or few symptoms. In some cases, however, it can be extremely aggressive and rapidly fatal. In 50% of cases when it metastasizes, it spreads only to the brain. Other locations that it favors include the other lung, the liver, the adrenal glands, and bone.

Click the icon to see an image of adenocarcinoma.

Bronchoalveolar Lung Cancer. Bronchoalveolar lung cancer is actually a subtype of adenocarcinoma. It develops as a layer of column-like cells on the lung and spreads through the airways, causing great volumes of sputum. This cancer also is increasing in incidence.

Text Continues Below

---

Large Cell Carcinoma. Large cell carcinoma, which makes up about 10% to 20% of lung cancers, includes cancers that cannot be identified under the microscope as squamous cell cancers or adenocarcinomas.

Click the icon to see an image of large cell carcinoma.

Small Cell Lung Cancer

Small cell lung cancer may, like squamous cells, be derived from reserve cells or other cells in the epithelium. It causes between 15% and 25% of all lung cancers; without chemotherapy, it is very aggressive and is usually rapidly fatal. It requires a different treatment approach from non-small cell lung cancer, so it is not discussed in this report.

Click the icon to see an image of small cell carcinoma.