Oat cell carcinoma, also known as small cell carcinoma, is a type of lung cancer that is characterized by small, oat-shaped malignant cells. The tumors generally consist of sheets of nearly identical cells with strands of connective tissue interspersed among them.

Under the microscope, it can be observed that these cells contain very little cytoplasm and have an appearance similar to normal lymphocytes, though the nuclei of the carcinoma cells are about twice the size of lymphocyte nuclei. Oat cell carcinoma is extremely aggressive and, in the majority of cases, by the time a diagnosis is made, the cancer has already metastasized to other parts of the body. Only about 30 percent of patients exhibit a limited form of the disease when they first seek medical attention.

Oat cell carcinoma accounts for approximately 15 to 20 percent of all lung cancer diagnoses. Most oat cell tumors initially form in a central location in the lungs, often in the major bronchial tubes. This origin of formation is consistent with the fact that smoking is well established as the primary contributing factor in the onset of oat cell carcinoma. Approximately 90 percent of people diagnosed with the cancer are, or were formerly, smokers. Thus, not smoking and avoiding secondhand smoke are the best ways to reduce one’s risk of developing oat cell carcinoma.

Some individuals do not experience any early symptoms of oat cell carcinoma, but frequently some problems do occur that may first bring the disease to the attention of a medical professional. These problems, which could be a sign of a number of other conditions as well, may include hoarseness, difficulty swallowing, a chronic cough, shortness of breath, coughing up blood, fatigue, loss of appetite, weight loss, chest pain, and facial or neck swelling. The seriousness of symptoms quickly amplifies in individuals with oat cell carcinoma and without treatment the median length of survival following diagnosis is only 2 to 4 months. The prognosis of specific individuals depends upon a number of factors, including the stage of the disease, gender, general health, and location of the tumors, but overall, the five-year survival rate is approximately 6 percent.

Due to the high metastatic rate of oat cell carcinomas, the cancer is rarely well suited for treatment by surgery, though in some limited stage cases of the cancer in which the lymph nodes are not involved it may be recommended. These less serious cases of the disease are usually associated with the periphery of the lungs rather than the more familiar central bronchial site. Much more commonly, chemotherapy, or a combination of chemotherapy and radiation therapy, is considered the preferred treatment for oat cell carcinoma. For individuals with widespread oat cell carcinoma, radiation therapy is usually only used to help relieve bone pain and other symptoms.

Oat Cell Carcinoma at 40x Magnification - Uranium and radium miners have been found to display a higher incidence of oat cell carcinoma than the general non-smoking population.

Oat Cell Carcinoma at 20x Magnification - Oat cell carcinomas have a tendency to metastasize rapidly, which means that signs of cancer in other areas of the body often appear in addition to symptoms of lung cancer.

Oat Cell Carcinoma at 10x Magnification - For some oat cell carcinoma patients, doctors may advise radiation therapy to the brain for tumors that have not yet spread to the central nervous system as a preventative measure.