Disseminated mycobacterium avium complex. Review of Ga-67 and TI-201 scans and autopsy findings.

A retrospective analysis of the files and Ga-67 scan findings of 32 AIDS patients with established diagnosis of disseminated Mycobacterium avium complex (MAC) was conducted in order to determine the sensitivity of Ga-67 scans for the diagnosis of this disease and the sites of MAC organ involvement. Fourteen of the 32 patients had early and delayed TI-201 scans that were also reviewed. Autopsy findings of AIDS patients in the 5 years (January 1990 to December 1994) were reviewed to determine the incidence and sites of involvement of disseminated MAC in AIDS autopsies. Chest x-ray was positive in only 41% of patients. Ga-67 scans were positive in 84% with multi-lymph node sites of involvement in 78% (hilar lymph nodes in 37.5%, supraclavicular 28.1% [all were on the left side], para-aortic 31.2%, paratracheal 18.2%, mediastinal nodes 6.2%, and axillary 3.1%), lung parenchymal in 18.7% and pleural in 9.3%). Increased uptake in the spleen in 16%, colitis 53.1% and enteritis 18.7%. Kaposi sarcoma in 9.3% and malignant lymphoma in 3.1%. TI-201 scans were only positive in 6 of 14 patients (42.8%). The autopsy data found the incidence of disseminated MAC in 23.7% (54 patients) out of a total of 228 autopsies. Approximately half of these cases (52%) were diagnosed antemortem. Other opportunistic infections were identified in 74%. The most common sites of MAC involvement were lymph nodes (74%), spleen (74%), liver (52%), lungs (22%), colon (13%), small bowel (11%), and bone marrow (9%). Associated Kaposi sarcoma was detected in 22% and non-Hodgkin's lymphoma in 13%. Problems in antemortem diagnosis were due to nonspecific presentations, involvement of intrathoracic and extrathoracic lymph nodes, liver, spleen and colon; and the higher incidence of opportunistic infections and negative chest x-ray in the majority of the patients.