Figure 1. Bone marrow core biopsy specimen shows loose collections of histiocytes (hematoxylin-eosin, original magnification ×400).
Figure 2. Small material (possibly organisms) is apparent on staining (Brown-Brenn, original magnification ×1000).
Figure 3. Small intracellular coccobacillary organisms consistent with Brucella species (Dieterle, original magnification ×1000).
Blood cultures were positive for Brucella melitensis and acute serum titers testing for Brucella species were positive at 1:320 by slide and tube agglutination. The bone marrow aspirate was not cultured; however, Dieterle stains of a bone marrow core specimen revealed small intracellular coccobacillary organisms within the histiocytic aggregates, consistent with Brucella species. No definitive organisms were seen on a tissue Gram stain, although several histiocytes contained small gram-negative material suspicious for bacterial organisms. The patient was treated with a 6-week course of gentamicin and doxycycline with resolution of symptoms and no recrudescence.