[Pathological anatomy of thymus gland tumors].

The paper presents detailed morphological characteristics of 31 thymomas and 25 microscopically similar neoplasias of the anterior mediastinum (carcinoid, seminoma, lymphogranulomatosis, angiofollicular lymphoma, etc). The term "thymoma" is determined as a tumour consisting of two components: mandatory epithelial one and lymphocytes. The diversity of the morphological picture of thymomas is determined mainly by the variability of the epithelial component. The special features of the ultrastructural organization of thymomas (the presence of desmosomes, tonofibrils and basal membrane) were revealed which facilitate the differential diagnosis of the anterior mediastinum tumours.