Ultrastructural aspects of chronic oral candidosis

Human biopsy specimens from white patches on the mucosae of tongue and lips which had previously given positive cultures for Candida albicans were examined. The specimens were processed for electron microscopy by conventional techniques. The fine structure of the superficial layer of the epithelium revealed Candida albicans in extra- and intracellular sites. Penetration into the deeper layers was not observed. The fungus had a thick cell wall surrounded by an outer floccular layer. The cytoplasm of the superficial epithelial cells showed degenerative changes and fragmentation of tonofilaments in the immediate vicinity of the fungus. Microabscesses, formed by pools of neutrophils, were common in the upper spinous layer. In places, fungi and bacteria appear to have been phagocytosed by neutrophils and macrophages. The cells of the lower spinous and basal layers showed detachment of desmosomes, marked increase in intracellular glycogen, prominent lysosome-like dense bodies and abundant mitochondria of differing shapes. At the epithelia-connective tissue junction, fine filaments and collagen fibrils were intermingled throughout the basal lamina, forming multiple, highly electron-dense layers. A noticeable change in the connective tissue was the accumulation of numerous mast cells containing differently shaped granules filled with scrolls and dense strands of granular material. The terminal blood vessel exhibited leakage and numerous, concentric duplications of the basal lamina.