Tumours

1. Benign epithelial proliferations

Squamous papilloma

• Most common oral neoplasm—believed to be caused by HPV

• Painless exophytic mass with warty surface, usually <>

or multiple; preferred sites are the palate, tongue, gingivae and lips

2. Premalignant lesions

Leukoplakia

• Clinical term for a white patch occurring on the surface of a mucous membrane

• In the mouth, the term is used to include only those white patches or plaques that will not rub off, and that are not caused by another oral disease

• Has been associated with tobacco smoking and alcohol abuse

• Most common in fifth to seventh decade; M>F

• Lesions may be localized or diffuse; vary from faintly translucent areas to thick fissured, indurated lesions

• 6% lesions will have carcinoma; additional 4% will undergo malignant transformation

Erythroplakia (erythroplasia of Queyrat)

• Initially described as syphilitic lesion of the glans penis—then recognized to also occur on vulva and oral mucosa in patients who are not syphilitic

• Sixth to seventh decades; M=F

• Defined as bright red velvety plaques not due to any other condition (e.g.gingivitis, candidiasis, hemangioma); unlike leukoplakia, almost all lesions will prove to be squamous dysplasia or carcinoma on biopsy

3. Malignant epithelial proliferations

Squamous cell carcinoma

• Account for majority of intraoral cancers; tobacco use and alcohol abuse implicated as causative factors; role of viruses (e.g. HPV,EBV) being investigated

• Predominantly affects males > 50 yr.

• Can present as mucosal ulcer, exophytic growth, endophytic growth, leukoplakia, erythroplakia or painless lymphadenopathy

• Commonest sites of involvement are the tongue, lip and floor of mouth

• Spread primarily by local extension and lymphatic dissemination; distant sites of involvement include lungs, bone and liver

• 5year survival rates are 75% for localized disease, 41% for regional cases and18% for cases with distant metastases

4. Nonepithelial tumours and tumour-like lesions

• Cysts of the gingiva, mucosa and jaw

• Benign soft tissue lesions (e.g. pyogenic granuloma, fibroma, schwannoma)

• Malignant soft tissue lesions (e.g. rhabdomyosarcoma)

• Lymphomas

• Odontogenic tumors (e.g. ameloblastoma)

• Tumours of the jaw (e.g. fibrous dysplasia, giant cell tumours, bone and cartilaginous tumours)

Category: Pathology Notes