Sunday, December 7, 2008

Answer to Case 48

Congratulations to Heather! She accurately identified this organism as Plasmodium vivax, based on the following features:

"amoeboid organisms; Schuffner's dots; 1 1/2-2X enlarged RBCs; light, "lacy" lavendar-colored organisms".

Great description. Based on the enlarged red blood cell and the stippling, your differential diagnosis would be P. ovale. However, this species produces trophozoites that are not amoeboid and much more compact. If you're 'lucky', RBCs infected with P. ovale are also ovoid with fimbriated edges, although this is only seen in a minority of infected cells.

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