Oral and maxillofacial pathology is the specialty of dentistry and pathology that concerns itself with the study, diagnosis, and management of developmental, inflammatory, infectious, neoplastic, and metabolic diseases relating to the teeth, the maxilla and mandible, the major and minor salivary glands, and the oral mucosa.
This chapter focuses on the more common oral mucosal diseases encountered in a pathology practice. As in the practice of dermatopathology, the importance of a thorough understanding of the clinical aspects and dynamic evolution of each entity cannot be overemphasized.
Synonym: Ectopic sebaceous glands.
Fordyce granules are intraoral sebaceous glands that are present in approximately 80% of the population1 and are viewed as a normal anatomic variation. They become prominent after puberty because of hormonal influences.
They occur as yellow papules measuring 1 to 3 mm in diameter and present symmetrically on the buccal mucosa, upper and lower lip mucosa, lip vermilion, and retromolar areas. Rarely, they also may be seen on the tongue, gingiva, and palatal mucosa.
They consist of normal sebaceous glands that may communicate with the surface epithelium via a duct. Occasionally, there may be hyperplasia of the sebaceous acini, retention of secretions with pseudocyst formation, and even adenomatous change.2 In one report, a hair follicle and hair shaft were present.
Most Fordyce granules are diagnosed on clinical findings alone, and there is usually no need for a biopsy. Some salivary gland neoplasms (especially those in the major glands) may exhibit focal sebaceous differentiation. Rare sebaceous adenomas or carcinomas may develop within the oral cavity but appear as obviously neoplastic processes.3
Synonyms: Leukoedema exfoliativum mucosae oris, congenital leukokeratosis mucosa oris, naevus spongiosus albus mucosae.
White sponge nevus (Table 37-1) is an uncommon mucosal condition transmitted in an autosomal dominant fashion with a high degree of penetrance and variable expressivity that affects primarily the oral mucosa, although genital, anal, laryngeal, and esophageal mucosal involvement also has been documented. There are no concomitant skin lesions, and ocular coloboma has been described in one report. White sponge nevus is the result of abnormal keratinization and faulty desquamation. This condition is caused by a mutation in differentiation-specific keratins K4 (on chromosome 12q) and/or K13 (on chromosome 17q) in a domain critical for keratin filament stability.4 A recent study suggested that abnormal degradation of the KRT13 protein may be associated with KRT7 and an abnormal ubiquitination process.5
TABLE 37-1White Sponge Nevus