Talaromyces marneffei

Background

• Previously known as Penicillium marneffei
• Dimorphic fungus within the Talaromyces

Clinical Manifestations

• Most common in patients with advanced HIV, in whom it most commonly causes disseminated infection
  • Subacute constitutional symptoms with hepatosplenomegaly, lymphadenopathy, and respiratory and GI issues
  • Skin lesions are a late manifestation, with central-umbilicated papules that start on face and spread to trunk and extremities
  • Often have cytopenias from bone marrow involvement

Diagnosis

• Microscopy shows round-to-oval extracellular and intramacrophage yeast-like organisms measuring 3 to 6 mum in diameter with presence of a clear midline septum in dividing yeast cell
• Culture
  • Grows readily in standard BACTEC blood culture media than other dimorphic fungi
  • Filamentous hyphae with characteristic spore-bearing conidiophores and conidia
  • Transitions from mold to yeast at 32 to 37ºC
• Histopathology may show one of three forms:
  • Granulomatous reaction formed by histiocytes, lymphocytes, epithelioid, and giant cells within the reticuloendothelial organs
  • Suppurative reaction that develops with the joining of multiple abscesses seen in the lung and subcutaneous tissues
  • Anergic, necrotizing reaction characterized by focal necrosis surrounded by distended histiocytes containing proliferating fungi

Management

• High susceptibility to amphotericin B, voriconazole, itraconazole1