[Mycobacterium kansasii seroma of the skin in HIV infection].

We report on an HIV-infected patient with AIDS in whom a smoothly demarcated area of resistance in the size of a fist was found on the inside of the thigh. Investigation by sonography for clinical differential diagnosis confirmed that a haematoma, a seroma or an abscess might be present. Upon puncture of the cavity, serous exudate was obtained. The microbiological investigation resulted in the growth of Mycobacterium kansasii. The detection of this agent in throat and sputum samples from the patient and the occurrence of an osteomyelitis lesion at the same time indicate that the seroma was a partial manifestation of a disseminated Mycobacterium kansasii infection. No indications of a transcutaneous route of infection was found. Upon antimicrobial chemotherapy after the determination of resistance the seroma disappeared.