History and admission findings: A 64 year old man complained about progressive pain in his right upper leg and pelvis since 4 weeks without any history of trauma. He noticed a reduced general health status for several months with weight loss and subfebrile temperatures. The patient's medical history revealed several malignant tumours and recurrent infections with atypical mycobacteria and herpes viruses.
Investigations: Laboratory findings showed signs of chronic inflammation. Multiple disseminated osteolytic bone lesions, hepatosplenomegaly, lymphadenopathy and multiple splenic lesions were detected by CT scan. Mycobacterium avium was isolated from an osteolytic lesion of the pelvic bone. Malignant disease and acquired immunodeficiency syndrome were excluded. Lymphocyte counts showed lymphocytopenia with reduced T cells, B cells and a reduced CD4-/CD8-ratio. Interferon-gamma-pathway defects as described in patients with susceptibility to atypical mycobacteria could not be identified.
Treatment and course: Clinical and immunologic findings indicated a link between recurrent Mycobacterium avium infections and an idiopathic CD-4 T-cell lymphopenia (low CD4 syndrome). Antimycobacterial treatment at standard doses was started according to the resistance test obtained from microbiological culture. Medical and radiological checkup after 3 months of therapy showed signs of progressive disease.
Conclusions: Osteolytic lesions can be caused by mycobacterium avium infection. Disseminated atypical mycobacteriosis is an opportunistic disease in patients with congenital or acquired immunodeficiency syndrome.