Bone marrow biopsies in patients with the acquired immunodeficiency syndrome.

Bone marrow biopsy findings in 32 homosexual patients with the acquired immunodeficiency syndrome (AIDS) or prodromal AIDS are described. A high incidence (38 per cent) of nonparatrabecular lymphohistiocytic infiltrations containing irregular small lymphocytes was observed, as well as the presence of diffuse bone marrow damage with plasmacytosis (22 per cent), decreased or absent stainable iron (50 per cent), and histologically identifiable pathogenic organisms (6 per cent). Morphologically, the lymphohistiocytic infiltrations are indistinguishable from bone marrow involvement by peripheral T-cell lymphoma, which may cause confusion, especially when a concurrent lymph node biopsy is difficult to interpret. On deeper sectioning, a specimen from one patient assumed a more granulomatous appearance. Specimens from two patients with small, poorly formed noncaseating granulomas contained demonstrable organisms.