INFLAMMATORY and ULCERATIVE LESIONS Aphthous Ulcers (Canker Sores): These lesions are extremely common, small (usually less than 5 mm in diameter), painful, shallow ulcers. Characteristically, they take the form of rounded, superficial erosions, often covered with a gray-white exudate and having an erythematous rim.
Identification of the inclusion-bearing cells or polykaryons in smears of blister fluid constitutes the diagnostic Tzanck test for HSV infection; antiviral agents may accelerate healing.
In the worst case, viremia may seed the brain (encephalitis) or produce disseminated visceral lesions.
Herpesvirus pharyngitis. A, Herpesvirus blister in mucosa. B, High-power view of cells from blister , showing glassy intranuclear herpes simplex inclusion body
HSV type 1 may localize in many other sites, including the conjunctivae (keratoconjunctivitis) and the esophagus when a nasogastric tube is introduced through an infected oral cavity.
HSV type 2 (the agent of herpes genitalis), on the other hand, is transmitted sexually and produces vesicles on the genital mucous membranes and external genitalia that have the same histologic characteristics as those that occur about the mouth.
This is a photomicrograph of infected cells, with inclusion bodies in both the nucleus and the cytoplasm.
Candida albicans is a normal inhabitant of the oral cavity found in 30% to 40% of the population; it causes disease only when there is some impairment of the usual protective mechanisms.
Oral candidiasis (thrush, moniliasis) is a common fungal infection among persons rendered vulnerable by diabetes mellitus, anemia, antibiotic or glucocorticoid therapy, immunodeficiency, or debilitating illnesses such as disseminated cancer.
Patients with the acquired immunodeficiency syndrome (AIDS) are at particular risk.
Typically, oral candidiasis takes the form of an adherent white, curd like, circumscribed plaque anywhere within the oral cavity.
The pseudomembrane can be scraped off to reveal an underlying granular erythematous inflammatory base .
Oral candidiasis ("thrush"). A white plaque like membrane coats the gingival mucosa of the left lower jaw in an edentulous young patient.
This pseudomembrane is composed of a layer of candidal
In the particularly vulnerable host , candidiasis may spread into the esophagus, especially when a nasogastric tube has been introduced, or it may produce widespread visceral lesions when the fungus gains entry into the bloodstream.
Disseminated candidiasis is a life-threatening infection that must be treated aggressively.
For poorly understood reasons, local candidal lesions may appear in the vagina, not only in predisposed persons but also in apparently healthy young women, particularly ones who are pregnant or using oral contraceptives or using broad-spectrum antibiotics.
As generally used, the term leukoplakia refers to a whitish, well-defined mucosal patch or plaque caused by epidermal thickening or hyperkeratosis.
The term is not applied to other white lesions, such as those caused by candidiasis, lichen planus, or many other disorders.
The plaques are more frequent among older men and are most often on the vermilion border of the lower lip, buccal mucosa, and the hard and soft palates and less frequently on the floor of the mouth and other intraoral sites.
They appear as localized, sometimes multifocal or even diffuse, smooth or roughened, leathery, white, discrete areas of mucosal thickening.
The treatment of leukoplakia mainly involves avoidance of predisposing factors — tobacco cessation, smoking, quitting betel chewing , abstinence from alcohol — and avoidance of chronic irritants, e.g., the sharp edges of teeth.
The overwhelming preponderance of oral cavity cancers are squamous cell carcinomas
Although they represent only about 3% of all cancers in the United States, they are disproportionately important. Almost all are readily accessible to biopsy and early identification.
These cancers tend to occur later in life and are rare before age 40.
The various influences thought to be important in development of these cancers are summarized in Table.
RISK FACTORS FOR ORAL CANCER Factor Comments Leukoplakia, erythroplasia May including tobacco, long-term alcohol use and other chronic irritants Tobacco use Best-established influence, particularly pipe smoking and smokeless tobacco Human papillomavirus types 16, 18, and 33 Identified by molecular probes in one half to one third of cases; early involvement in carcinogenesis is hypothesized Alcohol abuse Less strong influence than tobacco Protracted irritation Weakly associated
These lesions may cause local pain or difficulty in chewing, but many are relatively asymptomatic and so the lesion (very familiar to the exploring tongue) is ignored.
The overall 5-year survival rates after surgery and adjuvant radiation and chemotherapy are about 40% for cancers of the base of the tongue, pharynx, and floor of the mouth without lymph node metastasis, compared with under 20% for those with lymph node metastasis.
When these cancers are discovered at an early stage, 5-year survival can exceed 90%.
Oral squamous cell carcinoma. Invasive tumor islands show formation of keratin pearls.