[Histonet] pneumocystis by polarization


Sue O'Brien, Histology Supervisor, at Burdette Tomlin Memorial Hospital, Cape 
May Court House, New Jersey, asks:

>>I was wondering if anyone else had tried Dr. Teisa An's method (published 
in the March 2004 issue of Arch. Pathol. Lab. Med.)? It utilizes pepsin, and 
then the PCP can be visualized via polarization. For those that have tried it, 
what do you think? It is very easy to do the procedure, but the results seem a 
little different (for someone used to looking at silver stained material).<<

The article is "The use of polarization microscopy in the diagnosis of 
pneumocystis pneumonia" by Teisa An MD and Pam Tabaczka BS(MT) in the pathology 
department at Harper University Hospital in Detroit MI (Dr. An's e-mail is tan at 
dmc.org.), in Arch Pathol Lab Med 2004;128:163-4. They write "When tissue 
sections that had been treated with pepsin and stained with hematoxylin only were 
examined under polarized light, the cyst forms of P carinii were observed as 
being clearly birefringent and were as numerous as when a Grocott methenamine 
silver-stained slide was examined."

This article is a good example of why I get the Archives because the College 
of American Pathologists sends it to me, but usually let it accumulate on top 
of the previous month's number. The authors report exactly one case, without 
even noting whether a pneumocystis control slide was positive, how they applied 
the pepsin, or what hematoxylin they used. They offer no relevant references, 
and no explanation of how the method might work. They don't mention that the 
present name of the human pathogen is Pneumocystis jiroveci. If the Archives 
is actually a refereed journal, then taunts about the umpire's seeing-eye dog 
are definitely in order.

Still, it couldn't hurt to try the method, but it's hardly ready for prime 

Bob Richmond
Samurai Pathologist
Knoxville TN and Gastonia NC
Histonet mailing list

<< Previous Message | Next Message >>