Sixty four biopsy specimens of oral Candida leukoplakias were examined. Histological sections were stained with periodic acid-Schiff (PAS) reagent and by Grocott's silver method. C. albicans isolates were cultivated from all the patients but fungal hyphae were proved histologically only in 23 of them. PAS-positive and Grocott-positive elements were exclusively observed in the superficial epithelial layers, e.g., the cornified layer and the stratum granulosum. The inflammatory reaction was characterized by an early phase during which polymorphonuclear cells predominated. The skeletal muscle fascicles immediately adjacent to the infected epithelium showed striking degeneration and atrophy associated with a marked infiltrate of chronic inflammatory cells.

The frequency of Candida sp. in biopsies of oral mucosal lesions.Pesqui Odontol Bras. 2003 Jan-Mar;17(1):89-93. Epub 2003 Aug 5.

Candidosis is the most common fungal infection in the oral cavity, and is usually associated with local and systemic predisposing factors. The occurrence and relevance of Candidal infection in oral lesions such as liquen planus, leukoplakias and carcinomas are still to be understood. The aim of the present study was to define the frequency of infection by Candida sp. on biopsies of oral mucosal lesions and associate its presence with malignant and dysplastic lesions. Histopathology reports issued between 1990 and 2001 inclusive were reviewed. Three sections of each mucosal biopsy were stained using the periodic acid-Schiff (PAS) technique. From the 832 biopsies 27.2% were PAS positive, of which 83.25% were obtained from male patients. There was positive association between fungic infection and mild, moderate and severe epithelial dysplasia, squamous cell carcinoma and hiperqueratosis (p < 0.05). There was no association between fungic infection and inflammatory fibrous hyperplasia, hyperkeratosis, lichen planus and pyogenic granuloma (p < 0.05). The frequency of infection in the tongue was significantly higher (p < 0.05) than in the other sites. Our results do not show a causal relation between Candida sp. and dysplastic lesions and carcinomas, but do confirm the higher presence of that microrganism in those lesions.

Histopathologic and ultrastructural studies of oral mucosa with Candida infection.J Oral Pathol Med. 1992 Apr;21(4):171-5.

Eighteen oral mucosal biopsies with Candida infection were studied with light and electron microscopy. Under light microscopy, candidal infected oral mucosa was classified with epithelial hyperplasia, 15 cases and epithelial dysplasia, three cases. Four of 15 epithelial hyperplasias showed marked parakeratosis, and high grade acanthosis with many eosinophilic cells in the spinous cell layers. Epithelial dysplasia was characterized by atrophy of the spinous cell layers and increased nucleocytoplasmic ratio in the basal cell layers. Ultrastructurally, candidal infected oral mucosa showed numerous small desmosomes and the interdigitation of cytoplasmic membranes between spinous cells in both epithelial hyperplasia and epithelial dysplasia. Moreover, eosinophilic spinous cells, observed predominantly in epithelial hyperplasia showed intricate arrangement of dense tonofibrils. These ultrastructural findings seemed to give rise to mechanical strength between spinous cells in oral mucous epithelium with Candida infection. Results in this study suggest that excessive hyperplasia of candidal infected oral mucosa might be a protective reaction to the invasion of candidal pseudohyphae, but not associated with precancerous conditions.

Pathogenesis and morphogenesis of candidiasis in immunosuppression.Arkh Patol. 1990;52(11):67-70.

In this review, the peculiarities of etiology, pathogenesis and morphogenesis of candidiasis in immunosuppression (IS) are discussed. It is noted that in mycotic complications of IS, along with C. albicans other less pathogenic Candida species play increasingly important etiological role. Sequential analysis of development and clinical course of candidiasis reveals that IS has profound effect on the different pathomorphogenetic stages, including fungal adherence to the epithelial surfaces, invasion in the host tissues, hematogenous dissemination and formation of secondary lesions, as well as on histo- and organ pathology, tissue and cellular responses to the pathogen.