Oral Cancer and Complications of Cancer Therapies _ _____________________________________________
One of four classifications is possible for all submitted samples. An inadequate category indicates that not enough of a tissue sample for a meaningful classification has been obtained. A negative classification means that no epithelial abnormality has been detected. An atypical sample is one that has some epithelial abnormalities whose diagnostic meaning is unclear. A positive classification indicates positive evidence of epithelial dysplasia or carcinoma [25]. Treatment from this point depends on the lesion classification. This is an expedient addition to the armamentarium of oral cancer screening devices. Of note, screening should be done by the clinician who has adequate illumination, visualization, and knowledge of how the tissues of the oral and maxillofacial complex appear in a healthy state. LESION DIAGNOSIS The most common sites of oral cancers are the tongue, lip, and floor of the mouth [3]. However, oral cancers associated with HPV16 and HPV18 may appear at less common sites, such as the tonsils, tonsil pillar and crypt, base of the tongue, and the oropharynx [3]. Given the pleomorphic nature of oral cancers, clinicians should not ignore a lesion because it does not appear malignant or because it is on a site less frequently targeted by squamous cell lesions. SQUAMOUS CELL CARCINOMA The oral malignancy responsible for more than 90% of the total cases of oral cancer is squamous cell carcinoma [26]. Squamous cell carcinoma is the result of uncontrolled dif- ferentiation of surface squamous cells of the oral mucosa into malignant cells. This is an aggressive lesion whose nests of malignant cells penetrate the basement membrane and the underlying connective tissue. Infiltration into the vascular and lymphatic circulation may occur early and facilitate metastasis. Continued proliferation can extend into the musculature and the supporting bone, with the capacity to destroy both. Upon histologic confirmation of a squamous cell carcinoma, surgery and radiotherapy should be scheduled as quickly as possible, because growth of the primary lesion and metastasis both occur rapidly; combined therapy may also include chemotherapy in later stages [26]. Squamous cell carcinoma can occur anywhere in the oral cav- ity. However, there are some areas of the mouth where these lesions occur more frequently than others. As noted, the most common sites of involvement are the tongue, lip, and floor of the mouth [21]. Many squamous cell carcinomas are located in areas that preclude visualization by the patient and can grow to larger sizes asymptomatically ( Image 1 ).
A gingival squamous cell carcinomatous lesion in a patient with HIV. Source: CDC/Sol Silverman, Jr., DDS Image 1 KAPOSI SARCOMA The remaining types of oral malignancies affect tissues within the oral cavity or the adjacent salivary glands. Kaposi sarcoma, mainly associated with late-stage human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), is one such malignancy. A rarity in the United States until the AIDS epidemic, Kaposi sarcoma has been identified as an AIDS-defining illness. The initial presentation of these lesions is usually on the skin, but oral manifestations occur frequently. The palate, gingiva, and tongue are the primary sites of the appearance of these lesions; however, they may occur anywhere in the mouth. The human herpesvirus-8 (HHV-8) is considered to be the etiologic agent of this malignancy [9]. The lesions of Kaposi sarcoma may be red, violet, dark blue, or black-blue and usually begin asymptomatically. This vascular malignancy is typically flat at its onset but progresses to form nodules that develop a spongy consistency. Their growth can interfere with swallowing and eating, and larger lesions bleed easily. Treatment is usually a combination of surgery and radiation therapy, which is taxing for patients with an advanced stage of immunosuppression ( Image 2 ). Other types of cancers that may occur in the oral cavity include lymphomas, melanomas, and cancer of the minor salivary glands. These cancers are rare; nonetheless, they should be considered as a part of differential diagnosis when a patient presents with oral lesions of unknown etiology.
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