Scanning electron microscopy of yeasts in seborrheic keratoses.

Lesions of seborrheic keratoses were studied by scanning electrom microscopy. Numerous yeasts were present on the karatinized cells and hairs associated with the lesions. Surfaces of some yeasts were smooth and others were ruffled. The ruffles suggested the presence of a glycocalyx. The yeasts exhibited the morphological features of Pityrosporum ovale.