Ultrastructural markers of human liver cryptococcosis in an immunocompetent patient: Lipid droplets, multilamellar bodies, megamitochondria, and syncytia.

The ultrastructure of the human liver infected with Cryptococcus yeast cells was investigated using transmission electron microscopy (TEM). Infected liver specimens were collected from a 3-year-old female diagnosed with liver cryptococcosis after clinical examination. TEM revealed several types of aberrant structures in different liver cell types. Filled with lipid droplets, stellate cells were evident in the patient's liver, indicating collagen assembly and liver cirrhosis. Kupffer cells, fibroblasts, and stellate cells had multilamellar bodies with multiple ring-like structures, implying the lysosome-mediated degradation of refluxed bile. Megamitochondria (∼50 μm in length) were found in hepatocytes. Fused Kupffer cells formed multinucleated giant cells (syncytia). These observations provide insights into the cellular responses of organs to opportunistic fungal pathogens in immunocompetent patients.