The clean-up display of lung cancer is naturally determined by its morphological features. Therefore, from a radiological standpoint, the most acceptable is the grouping of primary lung cancer based on its anatomical shape and localization. According to this, lung cancer is divided into central, peripheral and bronchioalveolar.
Central cancer is a tumor emanating from large bronchi (segmental, lobar, major). It can grow predominantly endobronchial, exobronchial or peribronchial.
Endobronchial cancer is very rare, even with very small sizes, leads to a narrowing of the corresponding bronchus. Therefore, its main radiological manifestations are signs of impaired bronchial patency. Depending on the degree of narrowing, this may be hypoventilation, valvular distention or atelectasis of the part of the lung ventilated by the affected bronchus. Hypoventilation is characterized by a moderate decrease in volume and pneumatization of the lung tissue, thickening of the vascular pattern. Atelectasis of the lung is significantly reduced in volume, intensively and uniformly shaded. Adjacent segments are compensatoryly increased in volume, their airiness is increased, the elements of the pulmonary pattern are fan-shaped apart and shifted towards the atelectasized zone. With the decline of a whole lobe, and especially of the lung, a narrowing of the intercostal spaces occurs, the corresponding half of the diaphragm rises, the mediastinum shifts to the side of the lesion. The contralateral lung is swollen compensated. Direct visualization of bronchial stenosis is possible with a tomographic study. Similar data gives and bronchography. But at present, this technique for the diagnosis of endobronchial lung cancer should be replaced by CT and bronchoscopy.
Exobronchial cancer has a node shape and is characterized by a predominant growth outside the bronchial wall, the patency of which therefore can not be disturbed for a long time. Radiologically, this variant of central cancer is displayed as a round shadow in the root or in the root zone of the lung. More clearly all the morphological features of the tumor and its connection with one of the large bronchi are established by tomographic examination. In the late stages, when nevertheless bronchial obstruction is impaired or lymphogenous metastasis occurs, the tumor itself does not differentiate in isolation, since its shadow merges with the shadow of the atelectasized part of the lung and with enlarged bronchopulmonary lymph nodes.