Fig. 15.2 Fibrousproliferations.(A)Fibroma.Smoothpinkexophyticnoduleonthebuccalmucosa.(B)Pyogenicgranuloma.Erythematoushemorrhagicexophyticmassarisingfromthegingivalmucosa.
Fibromas are submucosal nodular fibrous tissue masses that are formed when chronic irritation results in reactive connective tissue hyperplasia (
Fig. 15.2A ). They occur most often on the buccal mucosa along the bite line. Treatment is complete surgical excision and removal of the source of irritation.
Fig. 15.2B ) is an inflammatory lesion typically found on the gingiva of children, young adults, and pregnant women (pregnancy tumor). These lesions are richly vascular and typically ulcerated, which gives them a red to purple color. In some cases, growth can be rapid and raise fear of a malignant neoplasm. However, histologic examination demonstrates a proliferation of immature vessels similar to that seen in granulation tissue. Pyogenic granulomas may regress, mature into dense fibrous masses, or develop into a peripheral ossifying fibroma. Complete surgical excision is definitive treatment.
Leukoplakia is defined by the World Health Organization as “a white patch or plaque that cannot be scraped http://ebooksmedicine.net off and cannot be characterized clinically or pathologically as any other disease.” This description is reserved for lesions that arise in the oral cavity in the absence of any known cause (
Fig. 15.3A ). Accordingly, white patches caused by obvious irritation or entities such as lichen planus and candidiasis are not considered leukoplakia. Approximately 3% of the world’s population has leukoplakic lesions, of which 5% to 25% are dsyplastic and at risk for progression to squamous cell carcinoma. Thus, until proved otherwise by means of histologic evaluation, all leukoplakias must be considered precancerous. A related but less common entity, erythroplakia, is a red, velvety, sometimes eroded lesion that is flat or slightly depressed relative to the surrounding mucosa. Erythroplakia is associated with a much greater risk for malignant transformation than leukoplakia. While leukoplakia and erythroplakia may be seen in adults at any age, they typically affect individuals between 40 and 70 years of age, with a 2:1 male predominance. Although the etiology is multifactorial, tobacco use (cigarettes, pipes, cigars, and chewing tobacco) is the most common risk factor for leukoplakia and erythroplakia.
MORPHOLOGYOnhistologicexaminationleukoplakiaanderythroplakiashowaspectrumofepithelialchangesrangingfromhyperkeratosisoverlyingathickened,acanthoticbutorderlymucosalepitheliumtolesionswithmarkedlydysplasticchangessometimesmergingintocarcinomainsitu(
Fig.15.3B ).Themostseveredysplasticchangesareassociatedwitherythroplakia,andmorethan50%ofthesecasesundergomalignanttransformation.Withincreasingdysplasiaandanaplasia,asubjacentinflammatorycellinfiltrateoflymphocytesandmacrophagesisoftenpresent.
Approximately 95% of cancers of the oral cavity are squamous cell carcinomas, with the remainder largely consisting of adenocarcinomas of salivary glands. Squamous cell carcinoma, an aggressive epithelial malignancy, is the sixth most common neoplasm in the world today. Despite numerous advances in treatment, the overall long-term survival rate has remained less than 50% for the past 50 years. This dismal outlook is due to several factors, in large part because oral cancer often is diagnosed at an advanced stage.