Extended and combined operations were more often performed with central lung cancer. Of the 1720 patients, 1300 (75.8%) had a central form of lung cancer, and only 420 (24.2%) had peripheral form. Data on the location of tumors in 1720 operated patients, taking into account their localization and shape (central, peripheral), are presented in Figure 8.
Women were operated on for peripheral tumors more often (40.4%) than men (29.8%), however, the differences in the ratio of central tumors to peripheral tumors in men and women were not statistically significant (p> 0.05).
An important biological criterion reflecting the features of the clinical course of lung cancer is its histological structure. According to some authors, the growth rate, degree of invasiveness and tendency to metastasis depend on the histological structure of the tumor, and it is also largely determined by
disease prognosis. Therefore, the morphological identification of lung cancer is of great practical importance in resolving issues of therapeutic tactics.
Pathological studies of biopsy material, surgical preparations and materials obtained in the study of sectional data of deceased patients were carried out at the Department of Pathological Anatomy of the Military Medical Academy of Adema , as well as at the Pathology Laboratory of the Department of Thoracic (State Nutritional) Surgery . Cytological studies were performed in the laboratory of the department . In order to clarify and detail the morphological structure of the tumor, to bring the pathological diagnosis into line with the current classification, associate professor I.A. Chalisov conducted a retrospective analysis of the entire archive of histological micropreparations belonging to the studied category of patients with low-grade forms of lung cancer.
A thorough histological study of the entire surgical material was performed to assess the prevalence of the tumor process, differential diagnosis with paracancrotic inflammatory changes. We studied the regional lymph nodes marked and removed during surgery. When studying a primary tumor in the lung, its location, size, and attitude to the bronchi, blood vessels, pleura, and extrapulmonary masses were evaluated. Plots of the lesions and organs of the thoracic cavity removed together with the lung or separately were subjected to a thorough histological examination to confirm their damage to the tumor tissue and to evaluate the radical nature of the operation performed.
In each observation during surgical interventions, a histological and cytological examination of a section of the distal end of the bronchus stump was performed to assess the radicalism of this stage of the operation.
The size of the primary tumor in the remote lung was determined by repeated measurement and dissection of the surgical preparation, delimiting the visible boundaries of blastomatous growth and inflammatory changes, if necessary, using a histological examination to clarify.
As a result of studies of lung tumors removed in 1720 patients who underwent extended and expanded combined resections, the following histological diagnoses were established: squamous cell with keratinization cancer in 266, squamous cell without keratinization in 823, moderately and highly differentiated adenocarcinoma in 126 and 505 patients different forms of low-grade cancer. In 65 (3.8%) cases, polymorphism of the histological structure of tumors was noted. It consisted of a combination of two or more forms of the histological structure of the tumor in one preparation, that is, there was a di- and polymorphic form of mixed cancer. When clarifying the issue of belonging to one or another histological form of lung cancer, it was assumed that the degree of malignancy and the tendency to metastasis are determined by cells with a lower degree of differentiation . In the case of a combination of equally differentiated histological structures, a quantitative predominant form of morphological structure was preferred. In each such specific case, the issue was resolved in a joint discussion of several morphologists. The most controversial and complex observations were brought up for discussion .