Increased secretion of serotonin, adrenocorticotropic and antidiuretic hormones, calciotonin and some others in patients with lung cancer can form Cushing’s syndrome, which then makes up a kind of “mask” of this disease. It should be noted that paraneoplastic syndromes in patients with lung cancer, especially of an undifferentiated structure, can occur in the early stages — several months or even six months before the appearance of other clinical signs of the disease. The correct interpretation of the various manifestations of paraneoplastic processes often allows one to recognize a malignant tumor in the lung behind these peculiar “masks”.

Paracancrotic inflammatory changes often significantly alter and even obscure the clinical manifestations of lung cancer. They occur in the tumor affected lung, pleural cavity and in the regional lymph nodes. The incidence of inflammatory paracancrotic processes in the lung increases with the growth and development of a cancerous tumor. Among patients with advanced stages of lung cancer, among those examined and operated on in our clinic, paracancrotic changes were found in 59% of cases. Moreover, the unfavorable combination of the effects on the patient’s organism of both products of tumor metabolism and purulent paracancrotic intoxication largely determines the uniqueness of the variants of the clinical course of the disease. The diverse and multifaceted manifestations of such secondarily occurring changes often occupy a leading place, pushing into the background, hiding the signs of lung cancer itself.

The most characteristic feature of paracancrotic changes in the clinical picture of central lung cancer are various manifestations of obstructive pneumonitis. As a rule, it is associated with impaired patency of the bronchus, concomitant changes in the mucociliary clearance system, accumulation of mucus and the development of infection distal to the obstruction. A feature of such obstructive pneumonitis in the initial period of lung cancer is the transience of its occurrence and reverse development under the influence of treatment, as well as recurrence. Later, with the progression of a blastomatous lesion, irreversible damage develops in the atelectasis zone. Then there is necrosis, tissue destruction with the formation of an abscess cavity or lung gangrene. Infection of the pleural exudate that often appears during this leads to the development of severe acute pleural empyema. The fate of patients with progressive destruction in the lung leads to a breakthrough of the abscess in the pleural cavity,

then accompanied by severe clinical manifestations of pyopnemothorax. Peripheral forms of lung cancer can also modify their clinical course, acquiring a “mask” of purulent-destructive process. The basis of such changes is the pathogenesis of peripheral cancer. The progressive growth of a spherical tumor in the lung naturally causes the destruction of blood vessels involved in the blastomatous process. Most of all this happens in its central departments. Then a zone of collication necrosis is formed here, which, when a tumor reaches one of the middle-caliber bronchi, becomes infected. In the center of the tumor, a purulent-destructive focus is formed. Its clinical manifestations at first are very similar to a blocked lung abscess, and after melting and emptying through the bronchus, with an incompletely drained abscess or suppuration cyst. All this is accompanied by the appearance in patients of complaints characteristic of such conditions, fever, separation with a cough of purulent, often fetid sputum. Clinical manifestations of parancrotic purulent-destructive changes in the lung and pleura usually also include pronounced general disorders. High fever is noted, often with hectic changes in body temperature, intoxication phenomena, respiratory distress and cardiovascular system activity. Volemic and other disorders characteristic of purulent-destructive lesions of the lungs develop. At this time, complaints and symptoms of the disease almost completely lose their traits pathognomonic for lung cancer. Such patients often aggressively associate the onset and first signs of their disease with these very most pronounced and especially disturbing manifestations of it. Moreover, they often do not even mention other previously existing health disorders that preceded its so noticeable deterioration. In connection with this, part of them goes for treatment to therapeutic, pulmonary or surgical hospitals, designed to assist patients with purulent diseases of the lungs and pleura.