Cytomegalovirus mononucleosis, peripheral blood.

 

Infectious mononucleosis, peripheral blood. These reactive atypical lymphocytes have pleomorphic reticular nuclei, peripheral basophilia of cytoplasm, and scalloped cell borders, some of which appears to stream into red cells. Slight rouleaux is also present.

 

Leishmaniasis associated with AIDS, bone marrow biopsy. Leishmania donovani are noted in macrophages. These parasites are similar in size to Histoplasma capsulatum, but the “double dot” appearance of the nucleus and kinetoplast is apparent in Leishmania (see center).

 

Striking dysgranulopoiesis associated with AIDS, bone marrow aspirate, May-Grünwald-Giemsa. One of the macropolycytes is likely to be tetraploid (92 chromosomes) and the other to have 138 chromosomes. A normal neutrophil is shown in the lower left for comparison.

 

HIV-associated lymphadenopathy, lymph node, H&E. Multinucleated cells are clearly appreciated, as is a venule.