Pathogenetic and clinical features of the disease were studied in 126 tuberculous patients living in the North of Russia. Tuberculomas in them were found to form primarily from a caseous-pneumonic focus, clinical symptoms were manifest. Anatomically, homogeneous tuberculomas predominated in the immigrants, while a laminar type occurred more frequently in the native population (34.5 +/- 0.14% against 4.5 +/- 0.16%).