Tumors of the Head and the Neck

By Dr. Vishaal Bhat on Monday 19 November 2007 with 0 comments



Malignant tumors of the head and neck represent about 10% of all statistically recorded tumors of malignant nature. At least 40% of them appear inside the oral cavity and on the lips. Oral cavity tumors are located on the mucous membrane of cheeks and the alveolar ridge, on the movable portion of the tongue (two frontal thirds), on the oral base and on the palate. Anatomical relationship of such tumors to the oropharynx (the tongue base, soft palate, palatal arches and tonsils) is very tight. Contribution of stomatology, oral, maxillar, and facial surgery to diagnostics and therapy of this group of tumors is thus more than obvious. The majority of orofacial tumors are epidermoid carcinomas derived from the mucous membrane of the mouth and oropharynx, as well as tumors originating from the lymphoid tissue of the Waldeyer’s ring. Lymphatic supply of these areas is achieved via the neck lymphatic system, consisting of regional submental and submandibular nodes, and nodes jugular, paravertebral and supraclavicular. Nearly one half of carcinomas of the oral cavity and oropharynx exhibit a presence of local metastases already at the time of diagnosis. This fact tells us about late recognition of the head and neck tumors. Non-characteristic initial signs, underestimation of the condition by a patient or even a physician, contribute to late diagnoses. Timely diagnosis of oral and oropharyngeal tumors plays an essential role for a prognosis. The presence of metastases decreases chances of patient’s survival for the next five years down to mere 25-30%.

Epidemiology

The oral cavity is a gateway to the upper airway-digestive tract. It comes into a close contact with carcinogens received in food and products of smoking and exhalations. The most significant risk factors for origination of oral carcinomas are tobacco and alcohol, whose carcinogenic potentiation effects have been proven. Currently, the peroral use of drugs, especially marihuana, is considered as an etiological factor.

Oral precancerous conditions (pre-neoplasias) cannot be overlooked here. The most characteristic among those are leukoplakia and erythroplakia of oral and lip mucosas. Leukoplakia may have either a benign form, with a typical parakeratosis or even acanthosis, and a malignant form with apparent signs of dysplasia or already as a carcinoma in situ. The origin of a malignant process may also be benign epithelial tumors of mucous papilloma type, if they get permanently irritated chemically or mechanically. During each examination of the mouth, especially by a dentist, it is reasonable to consider possibilities of chronic irritation or traumatization of mucosa by dental materials and fault intra-oral prosthetic constructions. An early elimination of carcinogenic causes is the most efficient prevention of a malignant process initiation (a secondary prevention). Every suspicious skin lesion that persists longer than 3 weeks has to be evaluated by a specialist. Histology testing of an excised tissue sample is then usually indicated.


Pathology

Absolute majority (up to 9/10) of oral and peri-oral tumors are epidermoid carcinomas at various stages of differentiation. Carcinomas of the lips, the tongue base and palate are usually well differentiated. Carcinomas of the oral base are partially differentiated, and carcinomas of the movable part of tongue are not very well differentiated at most cases. Low degree of differentiation has been proven to influence a disease prognosis unfavorably. Other tumors of non-epidermal origin occur at salivary glands (mixed tumors, adenoid cystic carcinomas), at the maxillary sinus (adenocarcinomas). Sarcomas penetrate the mouth mostly from jawbones and maxillary sinuses. Lymphomas affect lymphatic components of the Waldeyer’s circle - nodes at the upper part of the neck (a regional lymphatic system).


Category: Featured , Stomatology Notes

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