Pathology of the Head and Neck

Lesions of Squamous Epithelium Chapter 1 7Fig. 1.6. Erythroleukoplakia of the buccal mucosa. The microscopicdiagnosis was atypical hyperplasia. Courtesy of Dr.D. Dovšak, Ljubljana, Sloveniadoes not highlight a particular causal agent and the lesionwould appear to be multifactorial [114, 342]. Therelatively common absence of well-known risk factorsassociated with oral cancer and a preponderance of elderlyfemale patients, may indicate a different pathogenesisof PVL-related, compared with non-PVL-related,cancer [32]. It appears most frequently in the buccalmucosa, followed by the gingiva, tongue, and floorof the mouth [322]. The severity of histologic featurescorrelates with duration of lesion, from benign keratoticlesion to verrucous hyperplasia, and finally, upto one of three forms of SCC: verrucous, conventionalor papillary types [32]. PVL should be considereda possible diagnosis when a specific discrepancy betweenbland histological features and aggressive clinicalcourse is established [114]. Whether verrucous hyperplasiaforms a separate stage in this series of histologicalfeatures shown by PVL is debatable, as thereseems to be considerable histological overlap betweenthis lesion and verrucous carcinoma. Thus, there areno convincing arguments that verrucous hyperplasiais anything other than a variant of verrucous carcinoma[327, 371, 390]. A mean time of 7.7 years was foundfrom the diagnosis of PVL to cancer development in70.3% of patients [322]. The treatment of PVL continuesto be an unsolved problem with high rates of recurrence,since total excision is rarely possible because ofthe widespread growth [32].Oral erythroplakia is much less common than OL.OE occurs most frequently in older men as a red maculaor plaque with a soft, velvety texture, quite sharplydemarcated and regular in coloration. The disease wasfound to have no apparent sex predilection and is mostfrequent in the 6th and 7th decades [319].The floor of the mouth, the ventral and lateral tongue,the retromolar region and the soft palate are the mostfrequently involved sites [47, 263]. OEs that are intermixedwith white areas are called erythroleukoplakia orspeckled mucosa and are believed to behave similarly topure OE. The red appearance of OE may be related toan increase in subepithelial blood vessels, a lack of surfacekeratin and thinness of the epithelium. Prior to aclinical diagnosis of OE numerous entities should be excluded,such as: median rhomboid glossitis, all kinds ofinjuries, infectious and allergic lesions, haemorrhages,vessel tumours, Wegener’s granulomatosis, etc. [47]. AlthoughOE is a rare lesion, it is much more likely to showdysplasia or carcinoma. Shafer and Waldron reviewedtheir biopsy experiences with 65 cases of OE: 51% of casesshowed invasive SCC, 40% were carcinomas in situor severe dysplasia, and the remaining 9% showed mildto moderate dysplasia [319]. In all red lesions of the oralmucosa that do not regress within 2 weeks of the removalof possible aetiological factors, biopsy is, therefore,mandatory.1.2.4.2 Laryngealand HypopharyngealLeukoplakia andChronic LaryngitisSquamous intraepithelial lesions appear mainly alongthe true vocal cords, and rarely in other parts of the larynx,such as the epiglottis. Two-thirds of vocal cord lesionsare bilateral [48, 178, 181]. They can extend overthe free edge of the vocal cord to its subglottic surface.An origin in, or extension along the upper surface of thevocal cord is less common [181, 194]. The commissuresare rarely involved [48]. Hypopharyngeal lesions arerarely found and are poorly defined [364].Laryngeal SILs do not have a single distinctive orcharacteristic clinical appearance and are variously describedas leukoplakia, chronic hyperplastic laryngitisor rarely erythroplakia. A circumscribed thickening ofthe mucosa covered by whitish patches (Fig. 1.7), or anirregularly growing, well-defined warty plaque may beseen. A speckled appearance of lesions can also be present,caused by unequal thickness of the keratin layer.However, the lesions are commonly more diffuse,with a thickened appearance, and occupy a large part ofone or both vocal cords (Fig. 1.8). A few leukoplakic lesionsare ulcerated (6.5%) or combined with erythroplakia(15%) [48]. Leukoplakic lesions, in contrast to erythroplakicones, tend to be well demarcated.The macroscopic features of hypopharyngeal andlaryngeal SILs are not as well defined as their counterpartsin the oral cavity and their relative importance isnot generally accepted. Most patients with SILs presentwith a history of a few months or more of symptoms;an average duration of 7 months has been reported[48]. Symptoms depend on the location and sever-