Microscopic Description -- HIV Positive Man Died Following Bleeding from Mouth and Nose



The spleen has distortion of the normal architecture. There are no distinct white pulp nodules. Multiple, large, pale areas are seen mixed with smaller hemorrhagic areas. The paler areas correspond to foamy eosinophilic macrophages. Some cells contain foamy eosinophilic material. The acid-fast stains show numerous acid-fast bacilli in these areas. Occasional large cells may correspond to megakaryocytes and there are occasional nucleated cell which may represent red cell precursors. A pulmonary hilar lymph node shows complete effacement of the nodal architecture. There are few lymphocytes present with numerous poorly-formed granulomas which reveal numerous acid-fast bacilli on acid-fast stain. The bone marrow shows an apparently hypercellular marrow (80 to 90% cellular) and trilineage hematopoiesis. However, there are numerous plump, foamy macrophages which when considered show the marrow cellularity to actually be decreased. The bony trabeculae are thinned. Acid-fast stain shows the foamy macrophages to contain numerous acid-fast bacilli.


Sections of the liver show distortion of the normal architecture by severe steatosis and bridging fibrosis forming cirrhotic nodules. There is very little to no active hepatitis. The fibrous tissue bands are fine in areas and go through the center of the lobules, highlighted by the trichrome stain. There is little hepatocellular regeneration. Acid-fast stain reveals bacilli within the macrophages in the areas of portal fibrosis. Occasional hepatocytes contain crescent-shaped cytoplasmic inclusions seen with an immunohistochemical stain for hepatitis B surface antigen.


Sections of the lungs show pleural thickening with extensive subpleural emphysema. Some of the alveoli contain smoker's macrophages and others appear to have fibrin strands and foci of chronic inflammation. Acid-fast stains show areas surrounding the bronchioles with macrophages containing acid-fast bacilli. Occasional cells within the alveolar spaces also contain acid-fast bacilli. Occasional giant cells are noted.


Sections of the mesentery show occasional chronic inflammation with macrophages which contain acid-fast organisms. The ileum shows a moderate degree of autolysis with occasional macrophages and chronic inflammation within the lamina propria. Acid-fast stain reveals multiple acid-fast bacilli within the macrophages in the lamina propria. The pancreas shows extensive fat necrosis and hemorrhage.


Acid-fast stain of the kidneys shows occasional cells in the glomerulus and the tubules packed with acid-fast bacilli.


Sections of the bilateral occipital lesions show a moderate to heavy atypical lymphoid infiltrate around small and medium-sized leptomeningeal blood vessels with extension into the underlying parenchyma and secondary infarction (see arrow). These cells have a medium-sized nuclei which are vesicular and occasionally contain distinct nucleoli and moderate amount of cytoplasm. Typical concentric reticulin fiber deposition is present.

Immunohistochemical staining shows majority of these cells to be positive for the pan B-cell marker, CD20. Similar cells are found around meningeal blood vessels at the level of the head of the caudate nucleus as well. Grocott methenamine-Silver, and Fite stains are negative for fungi and mycobacteria, respectively in this section. Grocott, Fite and acid-fast stains are all negative as are stains for Varicella zoster virus and cytomegalovirus.

Cardiovascularsystem is unremarable.


Blood: no growth
Peripancreatic fat:heavy Klebsiella pneumoniae, heavy Proteus mirabilis
Kidney:heavy Klebsiella pneumoniae, heavy Proteus mirabilis
CSF:light Klebsiella pneumoniae
Liver:light Klebsiella pneumoniae
Lung:heavy Klebsiella pneumoniae
Spleen:light Klebsiella pneumoniae
Blood:Klebsiella pneumoniae
All cultures negative
All cultures negative
Peripancreatic fat:Mycobacterium avium complex
Kidney:Mycobacterium avium complex
CSF:Mycobacterium avium complex
Liver:Mycobacterium avium complex
Lung:Mycobacterium avium complex
Spleen:Mycobacterium avium complex



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