Alternariasis: ultrastructure of skin granuloma.

An ultrastructural investigation of dermal altenariasis has complemented previous studies. Alternaria tenuis was seen to be profusely present within the cytoplasm of multinucleate giant cells. Healthy elements were characterized by a thick, electron-lucent wall, ovoid osmiophilic inclusions and a poorly defined nucleus. Homogenous liquefaction and granular degeneration represented various types and steps of degradation; the wall subsisted for a while before collapsing and breaking into pieces. Penetration of the giant cell's cytoplasm within hollow tubes was observed.