| Pneumocystis
carinii (PC) is a fungus. It has world wide distribution. PC is
usually found in the interstitial fluid in the lungs of immunocompromised
patients (may disseminate to other organs). Detection of PC is carried
out by various methods such as Gomori Methenamine Silver (GMS), Giemsa,
Toludine O Blue, Papanicolaou, Fungi-Fluor & Immunofluorescent Antigen
(IFA). However, GMS & IFA remain gold standards for PC detection.
BAL and induced Sputum specimens are usually
requested for PC detection. Fungi-Fluor is routinely done for the detection
of fungal elements that is useful to detect PC as well, however, I have
found Gram stained smears extremely useful not only for bacterial detection
but also to suspect other organisms such as PC. The objects seen in
the Gram smear may not be so clear, however they produce morphology
of certain organisms that need to be identified. It is interesting to
know that PC may be suspected in ZN or even in Wet Preparation such
as KOH. Different staining procedures have been used to detect PC. However
IFA, Fungi-Fluor and GMS are extremely comparable procedures to detect
PC. Some clues provided in the Gram smears are worth to suspect PC in
the event when PC analysis is not requested by the clinician.
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