Visceral leishmaniasis — DTM&H MCQ

Correct answer: A — Bone marrow aspirate for Leishman-Donovan bodies

The correct answer is A, bone marrow aspirate for Leishman-Donovan bodies. This patient's presentation, chronic fever, marked weight loss, massive hepatosplenomegaly and pancytopenia in a resident of Bihar (the classic endemic focus for Leishmania donovani in the Indian subcontinent), is textbook visceral leishmaniasis (kala-azar). Diagnosis requires histological demonstration of amastigotes (Leishman-Donovan bodies) within macrophages, and bone marrow aspiration is the standard, safest tissue sample used routinely for this in clinical practice. Although splenic aspirate is more sensitive, it carries a real risk of fatal haemorrhage, especially with the marked thrombocytopenia seen here, so bone marrow is the appropriate first-line invasive test. This combination of geography, organomegaly and cytopenias should immediately trigger consideration of kala-azar over other tropical or haematological diagnoses. Why the other options are wrong: E. Peripheral blood thick film for malaria: Malaria can cause fever and splenomegaly but does not typically produce this degree of sustained wasting, massive splenomegaly over two months, and severe pancytopenia; the endemic and clinical picture here is far more consistent with kala-azar. D. CT abdomen and lymph node biopsy: This is invasive, non-specific for the parasite, and not the diagnostic method of choice for visceral leishmaniasis; lymphadenopathy is not a prominent feature of Indian kala-azar. C. Abdominal ultrasound with splenic aspiration: Ultrasound is useful for assessing organomegaly but adds nothing diagnostic here, and splenic aspiration, while highly sensitive, is unsafe with a platelet count of 65 due to haemorrhage risk. B. Serology for Epstein-Barr virus: EBV causes acute glandular fever type illness, not a two month wasting illness with massive splenomegaly and pancytopenia, and would not be first-line in an endemic kala-azar setting. Key point: Chronic fever, wasting, massive spleno-hepatomegaly and pancytopenia in a Bihar resident is kala-azar until proven otherwise, and bone marrow aspirate for Leishman-Donovan bodies is the practical diagnostic test of choice given the bleeding risk of splenic aspiration.

Reference: GPnotebook, Visceral leishmaniasis: diagnosis is by histological demonstration of the parasite (Leishman-Donovan bodies) in splenic aspirate, bone marrow or lymph nodes, https://gpnotebook.com/en-IE/pages/haematology/visceral-leishmaniasis