Penicillium marneffei Infection in AIDS

Table 2

Distinguishing features of microorganisms which may be confused with Penicillium marneffei in tissue examination [40, 56, 57].

	Similarities	Differences
Histoplasma capsulatum	Yeast cells with similar staining properties and size; Found within histiocytes and similar inflammatory response	Budding instead of septated yeast cells
Pneumocystis jiroveci	Cyst form similar size stained positive silver methenamine stain	Round cysts containing single or paired comma shaped argyrophilic foci in walls
Leishmania spp.	Amastigotes within histiocytes in H&E section	Presence of bar shaped kinetoplasts within amastigotes seen under oil immersion, PAS stain negative
Toxoplasma gondii	May appear as intracellular organisms in H&E section or Giemsa stain	Size smaller, can be found within in other somatic cell types, not stained with silver methenamine

H&E: haematoxylin and eosin; PAS: periodic acid-Schiff.