Answer: Visceral leishmaniasis due to Leishmania species (Leishmania donovani complex or L. tropica). As noted by Brady Page, Anon, Florida Fan, William Sears, and Daniel Skipper, the diagnosis can be easily secured by identifying the amastigotes within mononuclear phagocytes. Each amastigote has a small eccentric nucleus and rod-shaped kinetoplast, giving the so-called "dot-dash" pattern (thank you @JClinMicro)
And thank you to our poet, Blaine, who gave us the following:
Every week I will post a new Case, along with the answer to the previous case. Please feel free to write in with your answers, comments, and questions. Also check out my image archive website at http://parasitewonders.com. Enjoy!
The Fine Print: Please note that all opinions expressed here are mine and not my employer. Information provided is for educational purposes only. It is not intended as and does not substitute for medical advice. I do not accept medical consults from patients.