Oro-facial Precancerous States - 2

By Dr. Vishaal Bhat on Wednesday, 7 November, 2007 with 0 comments

Obligatory precancers include the following skin and mucous lesions: keratoses (solar-induced and actinic), xeroderma pigmentosum, morbus Bowen, erythroplasia Queyrat, cheilitis abrasiva praecancerosa, lentigo maligna and leukoplakias.

  • Keratoses are probably the most frequent epidermal precancers. They appear at elderly people on the face skin and mucosa of the lips, exposed to light rays or radiation. Keratoses have an appearance of multiple dry and adhering flakes, sometimes forming a cutaneous horn (cornu cutaneum). Histology reveals a dominant hyperkeratosis and nuclear abnormalities at the epidermal cells. Keratinoses of an actinitic origin have a 25% chance to be transformed into a flat-cell carcinoma.

  • Morbus Bowen is manifested as an isolated, flaky focus of psoriatic look which appears independently of the exposure to solar or other kinds of irradiation. Some pathologists consider it as a carcinoma in situ (intraepithelial carcinoma that does not overlap the mucosa basal membrane). A histological picture shows cellular polymorphism, nuclear abnormalities, atypical mitoses and other signs of malignant transformation of this lesion. Morbus Bowen may also appear on the mouth mucosa, namely at the retro-molar area and gingiva. The stage of development of this precancer is determined by an actual degree of proliferation activity (number and quality of mitoses) which can be assessed only histologically.

  • Xeroderma pigmentosum is characterized by focal hyperpigmentation of the skin of the face, flaking, atrophy and inflammation of the skin stroma. An inflammatory hyperplastic stage is followed by a proliferative process in the skin. Epidermal, as well as mesenchymal malignant tumors may develop from these foci. Again, a diagnosis can be clarified by histological examination only.

  • Erythroplasia Queyrat is characterized by red colored area located mostly at the border of the skin and lip mucosa, although it may be found on the oral mucosa as well. It is a network of capillaries that can be seen underneath a thin, pigment-lacking layer of horny cells. Based on degenerative and atrophic processes, a precancer with high proliferative tendency may develop. For this reason, the erythroplakia is already considered as a carcinoma in situ. A histological verification only can provide for conclusive results.

  • Cheilitis abrasiva praecancerosa, as an obligatory precancer, is commonly derived from a facultative actinitic cheilitis. It affects large sections or even the whole vermilion of the lower lip. At the stage of confluent erosion it already possesses signs of a carcinoma in situ. The precancer may be obscured by a clinical picture of inflammation and escape from identification for a long time.

Category: Featured , Stomatology Notes



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