Dissemination is the spread of the pathogen or tumor cells from the primary focus of the disease throughout the organ or body. This is carried out through the bloodstream and lymphatic system. After dissemination, a generalization process usually occurs, which is the development of many foci. Such secondary manifestations are called metastases.
Types of foci of diseases and their characteristics
The presence of foci in the body with pathological shadow sizes from 1 to 10 mm means that dissemination is occurring. These may be sites that differ in pathogenesis and morphological structure. They are inflammatory and non-inflammatory, fibrosed. In general, they can be an accumulation of tissues and cells. In the area of inflammatory foci, a process of a perifocal nature occurs. In addition, such areas tend to merge. At the same time, they begin to resemble an infiltrative-pneumatic process. With lung damage, bilateral pathology is noted. Some differences in diagnosis should be mentioned here. Previously, such processes were commonly called diffuse pulmonary diseases. However, total defeat cannot always be observed. In this regard, the name "disseminated" in this case is more suitable. Changes may not be diffuse.
Symptoms
Dissemination is an X-ray definition that includes about a hundred different diseases. They can occur with all kinds of symptoms. Dissemination in the lungs is usually accompanied by an inflammatory process of pleura. Symptoms are twofold. In inflammatory diseases, intoxication and hypoxia syndrome occurs. Against the background of disseminated lung cancer and carcinomatosis, respiratory failure progressing with the further development of pathology. Pulmonary dissemination is difficult to diagnose. That is why there is a high probability of error. For a more accurate diagnosis, a complete examination of the patients is necessary.
Classification of pathologies
Diseases in which dissemination occurs are:
- alveolitis (toxic fibrosing, exogenous allergic alveolitis, Hammen-Rich syndrome, microlithiasis, proteinosis);
- granulomatosis (pneumoconiosis, sarcoidosis, disseminated tuberculosis, pneumomycosis, histiocytosis);
- inflammation accompanied by tumor formations (carcinomatosis, bronchoalveolar, metastatic cancer);
- rare diseases (Goodpasture syndrome, idiopathic hemosiderosis, leiomyomatosis);
- interstitial fibrosis, which is formed when other organs and systems are damaged (collagenosis, radiation injuries, cardiogenic sclerosis, as well as sclerosis with liver disease).
Signs
Along with general, individual signs are also observed, indicating the development of disseminated processes. Knowledge and the ability to recognize them greatly facilitate the diagnosis. With pulmonary fibrosis, a moderate narrowing of the pulmonary fields occurs. Their transparency is also reduced. Changes in the tuberculosis form are located in the upper parts of the lungs. But diffuse pneumosclerosis is more pronounced in the lower part. Cancer metastases are located alone in the middle section of the lungs, and with carcinomatosis, a large number of nodes are observed. With tuberculosis, the foci have various sizes, their localization is subpleural. In the case of pneumoconiosis, the pathological process progresses in the lower lymph nodes, then granulomas occur, then the tissues are sclerosed. The remaining dissemination processes are much worse diagnosed, therefore a complex of laboratory examinations is needed.