- Visceral leishmaniasis (kala-azar) commonly causes pancytopenia due to the infiltration of the bone marrow by Leishmania parasites and consequent suppression of hematopoiesis.
- Additionally, splenomegaly leads to increased sequestration and destruction of blood cells.
- This results in anemia, leukopenia, and thrombocytopenia, which collectively define pancytopenia.
- Hypercalcemia, polycythemia, and leukocytosis are not characteristic features of untreated visceral leishmaniasis.
- Thus, pancytopenia is the hallmark hematological complication.

Reference: Davidson’s Principles and Practice of Medicine, 23rd Edition, Chapter: Tropical Medicine, Page 1162.