An HIV-positive patient (CD4 count 50 cells/uL) living in southern India presents with fever, weight loss, generalized lymphadenopathy, hepatosplenomegaly, and multiple skin papules with central umbilication resembling molluscum contagiosum. Bone marrow smear shows intracellular yeast-like organisms dividing by transverse septation (fission). The most likely diagnosis is:

• A Histoplasma capsulatum infection
• B Leishmania donovani infection
• C Trypanosoma cruzi infection
• D Talaromyces (Penicillium) marneffei infection ✓

Explanation

Talaromyces marneffei, formerly Penicillium marneffei, is a thermally dimorphic fungus endemic to Southeast Asia and southern China, an important opportunistic pathogen in AIDS patients there. In tissue at body temperature it forms yeast-like cells that divide by binary fission through a central transverse septum, producing elongated cells; this distinguishes it from Histoplasma, which buds and lacks a septum. Leishmania shows kinetoplast-bearing amastigotes without central septa.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.