2. Tumours of the maxillofacial region

Tumours of the maxillofacial region

OVERVIEW

• Maxillofacial tumours arise from oral mucosa, odontogenic tissues, salivary glands, bone, cartilage, connective tissue, skin, lymphoid tissue and metastatic deposits.
• Lesions may be benign, locally aggressive or malignant.
• A persistent ulcer, unexplained swelling, non-healing extraction socket, paraesthesia, tooth mobility, cervical node or progressive facial asymmetry warrants assessment.
• Tobacco, alcohol, betel quid, ultraviolet exposure, oncogenic viruses, prior radiation and genetic syndromes are relevant risk factors depending on tumour site.

ANATOMICAL APPROACH

• Record the precise subsite: lip, oral tongue, floor of mouth, buccal mucosa, gingiva, hard/soft palate, retromolar trigone, maxilla, mandible, paranasal sinus, skin or salivary gland.
• The oral cavity drains to submental, submandibular and deep cervical nodes.
• The parotid gland is traversed by the facial nerve; the submandibular gland lies close to the lingual and hypoglossal nerves.
• The maxilla communicates with the orbit and maxillary sinus; mandibular invasion can affect the inferior alveolar nerve and inferior border.

CLASSIFICATION

• Benign lesions include odontogenic cysts and tumours, osteoma, fibrous dysplasia, haemangioma/vascular malformation and benign salivary tumours such as pleomorphic adenoma.
• Malignant lesions include squamous-cell carcinoma (the commonest oral malignancy), mucoepidermoid carcinoma, adenoid cystic carcinoma, osteosarcoma, lymphoma, melanoma and metastases.
• Odontogenic tumours include ameloblastoma, which is benign but locally destructive, and malignant odontogenic entities.
• Distinguish true neoplasms from cysts, inflammatory swellings and developmental lesions.

BIOLOGY AND SPREAD

• Tumour behaviour depends on histology, grade, size, depth of invasion, perineural/lymphovascular invasion and anatomical barriers.
• Oral squamous carcinoma spreads by local infiltration and lymphatics; advanced disease may invade mandible, tongue musculature or floor of mouth.
• Salivary adenoid cystic carcinoma is notable for perineural spread and late distant metastasis.
• Bone tumours may cause cortical expansion, destruction and pathological fracture.

CLINICAL FEATURES AND EXAMINATION

• Ask about duration, growth rate, pain, ulceration, bleeding, dysphagia, odynophagia, speech change, trismus, numbness, weight loss, tobacco/alcohol exposure and previous cancers.
• Examine the lesion's size, site, surface, fixation, induration, depth and relation to teeth.
• Assess mouth opening, tongue mobility, floor of mouth, salivary duct openings, cranial nerves and dentition.
• Palpate both sides of the neck for nodal disease and document node level, size, mobility and tenderness.
• Examine skin and salivary glands; assess airway and nutrition in advanced disease.

INVESTIGATIONS

• Biopsy is essential for diagnosis in most suspicious mucosal lesions.
• Incisional biopsy is generally used for large or suspicious lesions; excisional biopsy may be appropriate for small lesions when planned by the treating specialist.
• Avoid unplanned excision of a suspected malignancy.