Oral Cavity Tumours - Malignant

Squamous Cell Carcinoma

Squamous cell carcinoma is the predominant type of malignant tumour in the oral cavity, while sarcoma, lymphoma are unusual and oral malignant melanoma a rarity [9] (one case per year in Sweden). Malignant melanoma is almost exclusively located in the upper part of the oral cavity (the hard palate). Pigmented transformations in other locations are usually benign. About half of all malignant oral tumours afflict the tongue, specifically the lateral edges.

Cancer of the tongue afflict men more often than women, predominantly at the age of >50 years, but even so, there is a noticeable increase among people under the age of 40 years. A majority of the tumours are ulcerous and infiltrative, rarely exophytic; the latter is more frequent when it evolves from a leukoplakia. More than 50 per cent of the tongue cancer cases metastasize and the metastasizing frequency correlates with the tumour size. Contralateral metastases are not uncommon, especially when the primary cancer is located near the midline. *CASE*

Buccal cancer is very common in India and adjacent countries, where chewing of betel and so-called inverted smoking prevails. It is less common in Sweden and is often discovered rather late as the buccal mucosa is less sensitive than the oral mucosa in general. *CASE* In buccal cancer the lymphatic gland metastasizing is around 40 per cent.

Cancer of the floor of the mouth seldom extends past the midplane, but propagates rapidly up through the tongue and/or the gingiva. In the clinical situation it can be difficult to determine if the tumour evolves from the floor of the mouth or the gingiva. Metastases can be found in 40-50 per cent of the cases at the time of diagnosis, notably in the submandibular gland. When palpating it can be difficult to decide if it is a case of metastasis or a direct tumour growth into the neck. *CASE*

In a gingival cancer of the lower jaw the tumour proliferates rapidly into the floor of the mouth, and in about 30 per cent of all cases the tumour affects the bony structures, which leads to more extensive surgery, and is unfavorable from a prognostic point of view. The metastatic frequency is the same as for floor of the mouth cancer (40-50 %).*CASE*

In a cancer of the upper jaw, or more seldom, cancer of the hard palate, the possibility of a downward spreading cancer from the maxillary sinuses must be taken into consideration. Verrucous cancer *CASE*is a special type of squamous cell carcinoma, which looks like intense hyperkeratosis (wart-like) and rarely metastasizes or grows infiltratively.

Lymphoma and Leukemia

The malignant lymphomas are split into Hodgkin’s disease, and non-Hodgkin-lymphoma. The latter is categorized as high-grade malignant and low-grade malignant types, respectively. Low-grade malignant non-Hodgkin-lymphoma is in many ways similar to chronic lymphatic leukemia, and these two conditions are often indistinguishable. Non-Hodgkin-lymphoma, and on rare occasions, Hodgkin’s disease can evolve from tumour formations in the oral cavity, but the site of origin is more often than not Waldeyer’s tonsillar ring. Such lymphomas often appear as subepithelial swellings, but ulcerating tumours can also be observed [9]. The site of origin can sometimes be the gingiva close to the teeth. Inflamed, rather superficial and often multiple ulcerations in the oral cavity are not unusual in chronic lymphatic leukemia as well as in acute leukemias.

The incidence rate for non-Hodgkin-lymphoma is rising quickly in Sweden, as well as the rest of the world. The reason for this is unclear. Viral genesis has been suggested, but has as yet not been confirmed. It should be added that only a small minority of lymphoma patients are HIV-positive. On the other hand a development of various lymphoid conditions is common in the terminal stage of this infection. It is, of course, of importance to always keep such a possibility in mind. *CASE*

Intraoral Metastases

Practically every generalized cancer disease may have oral manifestations [9]. The clinical situation is often otherwise clear with symptoms of advanced disease, normally lung or prostratic cancer *CASE* . It is very uncommon for a malignant tumour of extraoral origin to to manifest itself with an oral cavity metastasis as the initial symptom. In rare cases it can be observed, especially in renal cancer. *CASE* The search for primary tumours usually have to wait until a morphological diagnosis of the oral cavity tumour has been secured. Quite often the pathologist can give clear indications as to where a primary tumour can be found.