Differential diagnosis of bacterial myositis in AIDS: evaluation with MR imaging.

Abstract

Magnetic resonance (MR) imaging was used to assess for the presence of bacterial myositis, rare outside the tropics, in 13 patients with either the acquired immunodeficiency syndrome (AIDS) (n = 11) or positive results of serologic tests for the human immunodeficiency virus but without other evidence of AIDS (n = 2). Bacterial myositis was diagnosed in six patients: in five it was caused by pyogenic bacteria, and in the other, by Mycobacterium tuberculosis; in each patient, little or no subcutaneous tissue alteration occurred. On T1-weighted images in three patients, muscle abscesses showed a rim of increased signal intensity corresponding to margins between drainable pus and edematous muscle. Subcutaneous tissues appeared normal in patients with bacterial myositis but was not in the others, in whom muscle abnormalities tended to be less prominent. The latter group included patients with lymphoma (n = 1), Kaposi sarcoma (n = 2), and carbunculosis (n = 1), and three patients in whom no diagnosis was made; lymphedema was presumed to account for imaging abnormalities in four of the latter group.

Skeletal muscle lymphoma in patients with the acquired immunodeficiency syndrome: a diagnostic challenge

“…Muscle infection by Staphylococcus aureus has been recognized with increasing frequency in AIDS patients (14,15), and pyomyositis must be considered in patients with fever and local inflammatory swelling, since it requires rapid surgical drainage and antibiotic therapy. In pyomyositis, the subcutaneous tissue is uninvolved clinically (14) and on MRI (4). Therefore, attachment of muscle mass to the overlying skin, as was demonstrated to result from subcutaneous tumoral infiltration by MRI and biopsy in our patients, is highly suggestive of NHL (4).…”

“…In pyomyositis, the subcutaneous tissue is uninvolved clinically (14) and on MRI (4). Therefore, attachment of muscle mass to the overlying skin, as was demonstrated to result from subcutaneous tumoral infiltration by MRI and biopsy in our patients, is highly suggestive of NHL (4). Finally, in rare cases, Kaposi's sarcoma may develop in the skeletal muscle of patients with AIDS (ref.…”

“…Finally, in rare cases, Kaposi's sarcoma may develop in the skeletal muscle of patients with AIDS (ref. 4 and Gherardi R: unpublished data).…”

“…Non-Hodgkin's lymphoma (NHL) is approximately 60 times more frequent in human immunodeficiency virus (HIVhinfected patients than in the general population (2), and extranodal presentation of NHL accounts for 55% of lymphomas in this setting (3). Despite occasional reports on skeletal muscle lymphoma in patients with the acquired immunodeficiency syndrome (AIDS) (3,4), NHL has not been mentioned in reviews on neuromuscular diseases associated with HIV infection (5-7). Herein we report 2 cases of muscle NHL in HIV-infected patients, who were initially thought to have pyomyositis or thrombophlebitis.…”

“…Painful unilateral limb swelling in HIV-infected patients may represent a difficult diagnostic challenge (4). Calf muscle lymphoma has been previously mistaken for deep vein thrombosis, which is common in patients with AIDS, especially in drug abusers (13).…”