Bronchiolar/Alveolar Carcinoma, Lung, Rat

While small tumors may not be visible to the unaided eye, most bronchiolar/alveolar carcinomas are of sufficient size to be easily seen. They appear as firm, pale, white to pink irregular smooth nodules projecting above the pleural surface. In advanced cases an entire lobe may be replaced by tumorous tissue. While in man they are most often found in the upper lobe, a site propensity has not been reported for the rat. When cut most will have a smooth surface, except for those containing areas of necrosis, which will appear grossly as yellow to pale brown irregular areas of soft caseous material within the tumor.