Osteomyelitis. A pathomorphologic overview

Abstract

Osteomyelitis is an infection of the bone marrow caused by both non-specific and specific agents. Non-specific endogenic osteomyelitis represents the most frequent form, followed by the specific form caused by Mycobacterium tuberculosis infection. Typically, the non-specific form occurs in children and young adults, and the sites most frequently affected are the distal and the proximal ends of the tibia and femur. In tuberculosis, osteomyelitis is predominantly located in the vertebral bodies. In rare cases osteomyelitis can be caused by viruses, fungi or echinococcus. It may also occur as so-called acute endogenic osteomyelitis, such as plasmocellular osteomyelitis and Brodie's abscess. Histologically, dense infiltration of leucocytes, granulation tissue and bone sequesters can be seen. In tuberculosis granulomas with central necrosis, epithelioid cells and giant cells of Langhans type are characteristically found. Most forms of acute osteomyelitis can be successfully treated with antibiotics, leading to complete healing without complications. Only a few reported cases develop into a secondary, chronic form.