Clinical History:

A 42-year-old man who had been known to be HIV positive for 10 years developed persistent fever with weight loss. Physical examination revealed hepatomegaly with splenomegaly, and lymph nodes were palpable in the posterior cervical region. A chest radiograph showed no infiltrates or masses. A lymph node biopsy was performed.

Answers:

1. What are the possible causes for these findings?

The organ involvement suggests a disseminated disease. Mycobacterial and fungal infections are the most likely possibilities with this clinical picture in the setting of HIV infection. Lymphoma is less likely, as it is usually extranodal in AIDS. Mycobacterial disease is suggested from the gross and microscopic findings. Miliary granulomas are present in the spleen. Numerous acid fast bacilli are seen in macrophages. Mycobacterium avium-complex (MAC) is more likely than Mycobacterium tuberculosis (MTB) with these findings. MTB is more likely to have pulmonary symptoms. Fungal infections such as Histoplasma capsulatum, Cryptococcus neoformans, and Coccidioides immitis could produce a similar clinical picture.

2. What laboratory testing or diagnostic procedures can be performed to reach a diagnosis?

Microbiologic culture of the lymph node, bone marrow biopsy, as well as a blood culture, can be of use.

3. What is his stage of HIV infection?

Given that a disseminated opportunistic infection is present, he is in Stage 3 of AIDS.

4. What laboratory testing is available to follow the course of his HIV infection?

The HIV-1 RNA levels in plasma have been utilized, and is very useful to determine response to anti-retroviral therapy (HIV-1 RNA levels should decrease with a good response to therapy).