Bronchogenic carcinoma refers to something that arises from the bronchi of the lungs. “Carcinoma” is the general term for malignant tumors (or “cancers”) that arise from epithelial tissue. A bronchogenic is a malignant tumor that arises from the epithelial lining tissue of the bronchi. The majority of bronchogenic carcinomas fall into one of four categories, based upon their histologic characteristics: (a) squamous cell (epidermoid) cancer, (b) small cell (oat cell) cancer, (c) large cell (anaplastic) cancer, and (d) adenocarcinoma. The first three types are strongly correlated with cigarette smoking. In fact, only about 2% of all lung cancers occur in non-smokers.

Normal bronchial epithelium is ciliated, pseudostratified, columnar epithelium. The appearance of cancerous tissue here would very depending upon the specific type of bronchogenic cancer the patient has. In squamous cell (epidermoid) cancer, the cells are flattened and produce an abundance of keratin, looking like epidermal cells of the skin (hence, the term epidermoid cancer). In small cell cancer, the cancer cells are oval-shaped and small with little or no cytoplasm visible. In large cell cancer, the cells are larger and very poorly differnetiated (i.e., immature in appearance), with large nuclei. Finally, in adenocarcinoma, cells may range from well-differentiated, glandular cells producing mucous to poorly differentiated cells packed more tightly together.

Bronchogenic carcinomas can spread directly to neighbouring parts of the bronchial tree or metastasize through lymphatic vessels to the more centrally located hilar and carinal lymph nodes. From these lymph nodes, cancer cells may continue to spread to the general circulation, reaching other organs such as the brain and the skeleton. Finally, bronchogenic carcinoma cells may metastasize directly to the bloodstream, bypassing the lymphatic vessels, ultimately reaching the brain, bones, liver, and adrenal glands.

Lung cancers are notorious for metastasizing early on in their development, sometimes even before they cause symptoms or show up on a chest x-ray. Hence, the cancer often has already spread to other parts of the body before the diagnosis is made. Once it has spread, it is much more difficult to treat. Squamous cell carcinomas grow somewhat more slowly than the other three types, and thus, in infrequent cases, can be successfully treated by surgical removal of the tumour. However, surgical, chemo-, and radiotherapy for all four major types of lung cancers are largely unsuccessful, and the prognosis for survival is poor. This makes prevention of lung cancer the only viable option. In this regard, the best thing an individual can do to avoid lung cancer is to avoid cigarette smoke.
- Bronchial carcinoma is the commonest cancer among men in the United Kingdom.  Four main histological types occur of which small cell carries the worst prognosis.  The overall prognosis remains appalling with only 10% of sufferers surviving 5 years.  It occurs most commonly in the mucous membranes lining the major bronchi near the hilum.  Local invasion and spread to hilar and tracheobronchial nodes occurs early.

Reference:
1. Anatomy at a Glance. Omar Faiz and David Moffat.  Blackwell Science. 2002.