A survey has been made of granulomatous lesions found in sections of bone marrow from 150 patients studied at the Mayo Clinic. These lesions have been found in a variety of disorders, some with known etiologic agents and others with unknown causes.

With the exception of tuberculosis, histoplasmosis and brucellosis, in which the causative organisms were seen and identified bacteriologically, the granulomatous lesions were not thought to have any distinctive histopathologic characteristics.

Prominent lesions, Langhans’ giant cells and necrosis were more common in the marrow of patients with disorders known to be associated with a granulomatous inflammatory process than they were in associations with other conditions.

This content is only available as a PDF.