Tumours of the head and neck
The concentration of anatomical structures and the rich traversing lymphatic system, bearing drainage from all parts of the body, explains the diversity of primary and secondary tumours found in the head and neck region. Exposure of the skin to ultraviolet B radiation results in 85–90% of cutaneous carcinomas, the most common human malignancy occurring in the head and neck area. Excluding cutaneous tumours, 90% of head and neck tumours are squamous cell carcinomas arising from the epithelium of the upper aero-digestive tract. These tumours are predominantly the result of the carcinogens released from tobacco, either due to smoking or chewing. Primary tumours, malignant and benign, can arise from all other structures; glandular, vascular, lymphatic, neural, muscular, bony or of connective tissue origin.
Metastatic tumours to the head and neck are predominantly due to lymphatic spread. Metastatic lymph nodes characteristically firm to hard and matted which are confined to the upper third of the neck are most commonly the result of tumour spread from a primary squamous carcinoma of the upper aero-digestive tract. Metastatic lymph nodes confined to the lower third of the neck are less commonly from an aero-digestive tract origin and more likely from primary sites such as skin, thyroid or a malignant focus below the clavicle. Rare blood-borne metastases are seen in the parotid gland from colon, kidney, breast and lung and in the thyroid from lung and kidney.
The common mode of presentation of head and neck tumours is that of a painless neck mass or swelling. The approach to solving the problem of a neck swelling is dealt with in detail in Chapter 67.
An understanding of the characteristic features of the common head and neck tumours and of the anatomy of the region should guide the clinician as to the likely diagnosis based on clinical assessment (see Table 39, “Tumours of the head and neck”). Treatment planning, however, requires a detailed assessment including endoscopy, accurate anatomical localisation with CT or MRI and pathological appraisal utilising the least invasive technique applicable. Needle aspiration cytology, either free hand for accessible masses or ultrasound guided for deeper tumours usually provide diagnostic material. Core biopsy or carefully considered open biopsy may be required if cytology is inconclusive.
|Tissue oforigin||Benign/malignant||Tumour type||Clinical site||Common clinical feature|
|Upper aerodigestive tract mucosa||Benign||Squamous papilloma||Oral cavity mucosa||Solitary papillary lesion|
|Malignant||Carcinoma in situ||Oral cavity larynx - pharynx||White or red mucosal patch|
|Squamous cell carcinoma||Mucosa of upper aerodigestive tract||Ulcerated, infiltrative lesion with raised edges|
|Lympho-epithelial carcinoma||Nasopharynx||Ulcerated lesion, frequent nodal metastases, nasal symptoms|
|Salivary gland||Benign||Pleomorphic adenoma||Parotid commonest||Painless, slow-growing firm mass|
|Oncocytic tumour (Warthin's tumour)||Parotid grand||Soft to firm, occasionally bilateral, mass|
|Malignant||Mucoepidermoid carcinoma||Parotid commonest||Slow-growing firm mass|
|Adenoid cystic||Minor salivary glands commonest||Slow-growing submucosal nodule in the upper aerodigestic tract|
|Acinic cell tumour||Parotid gland||Slow-growing nodule|
|Adenocarcinoma||Minor salivary gland||Submucosal lump|
|Thyroid||Benign||Follicular adenoma||Thyroid||Slow-growing smooth thyroid nodule|
|Hurtle cell adenoma||Thyroid||Slow-growing smooth thyroid nodule|
|Malignant||Papillary carcinoma||Thyroid gland +/− nodes||Slow-growing nodule. 50% children have associated nodal metastases|
|Follicular carcinoma||Thyroid||Slow-growing smooth thyroid nodule|
|Anaplastic carcinoma||Thyroid||Rapidly growing infiltrating mass often arising within a pre-existing goitre|
|Medullary carcinoma||Thyroid +/− nodes||Firm thyroid nodule, may be associated with multiple endocrine adenoma syndrome|
|Parathyroid cells||Benign||Parathyroid adenoma||Parathyroid glands (Impalpable)||Commonest cause of primary hyperparathyroidism.|
|Malignant||Parathyroid carcinoma||Parathyroid +/− nodes||Progressive hyperparathyroidism. Nodule may be palpable|
|Neuroendocrine||Benign||Paraganglionoma||Carotid body||Mass in region of upper carotid sheath.|
|Glomus intravagale||Occasional symptoms resulting from noradrenaline secretion|
|Malignant||Olfactory neuroblastoma||Olfactory mucosa in nasal vault||Bimodal age distribution occurring in adolescents and adults. Epistaxis and nasal obstruction|
|Adipose||Benign||Lipoma||Commonest in subcutaneous layer||Mobile superficial soft mass|
|Malignant||Liposarcoma||Neck, larynx, pharynx||Rare head and neck tumour. Occurs in elderly patients|
|Vascular||Benign||Haemangioma||Face, scalp, neck||Seen in childhood. Compressible red to purple mass|
|Lymphangioma||Neck||Soft, occasionally translucent neck mass in children|
|Malignant||Angiosarcoma||Skin of scalp or face||Ulcerating cutaneous nodule occurring in elderly white males|
|Fibrous tissue||Benign||Fibromatosis||Commonly in neck||Slow-growing mass in young females|
|Dermatofibroma||Skin||Small plaque in skin|
|Malignant||Fibrosarcoma||Face, neck, scalp and paranasal sinus||Painless growing mass in adults|
|Malignant fibrous histocytoma||Deep tissues of head and neck||Infiltrating mass in elderly males. Commonest post-irradiation tumour|
|Neural tissue||Benign||Schwannoma||Cranial nerves VIII, IX, X, XI and XII||Lateral neck mass|
|Neurofibromas||Peripheral nerve sheaths||Isolated subcutaneous neck nodule, or multiple nodules nd large plexiform benign neuromas in familial neurofibromatosis|
|Malignant||Malignant schwannoma||Cranial and cervical nerve roots||Fixed mass. Metastases possible|
|Muscle cell||Malignant||Rhabdomyosarcoma||Orbit, nasal cavity and paranasal sinuses||Commonest soft tissue sarcoma seen in children|
|Bone||Benign||Osteoma||Bony skeleton of face||Smooth mass occurring in paranasal sinuses; multiple osteomas associated with Gardner's syndrome|
|Malignant||Osteosarcoma||Mandible or maxilla||Painless enlarging bony swelling|
|Skin||Malignant||Squamous cell carcinoma (SCC)||Sun-exposed skin||Crusting ulcerating lesion|
|Basal cell carcinoma (BCC)||Skin of central face||Translucent nodular lesion. Rarely a deeply ulcerating or erosive lesion.|
|Malignant melanoma||Skin of face. Mucosa of nasal cavity||Pigmented skin lesion or polypoid nasal mass|
|Lymphoid tissue||Malignant||Lymphoma||Lymphatic tissue, salivary glands, thyroid||Rubbery, discrete, multiple neck nodes|
|Dental tissue||Benign||Ameloblastoma||Usually intra-osseous but may involve the gingiva||Expanding mass arising in association with mandible. Rarely malignant|
|Squamous ontogenic tumour|
Characteristics of common tumours
Squamous cell carcinoma
The commonest head and neck malignancy is squamous cell carcinoma rising from the upper aerodigestive tract. Full details of this problem are covered in Chapter 38.
Cutaneous squamous cell carcinoma
The lips, forehead and ear are the commonest sites for squamous carcinoma of the head and neck due to their exposure to sunlight. Lesions vary from an area of crusting through to ulceration and induration. Squamous cell carcinoma (SCC) of the upper lip has a higher propensity for lymph node metastasis than SCC arising at other sites. SCC of the temple and ear may metastasise to the pre-auricular intra-parotid lymph nodes. Such metastasis may appear some time following successful local excision of the primary tumour. Involvement of the facial nerve from intra-parotid metastasies carries a very poor prognosis. Metastatic lymph nodes from a cutaneous SCC, like those from an aerodigestive tract origin, often undergo cystic degeneration. Rapid growth, redness of the overlying skin and clinical fluctuance can lead to the mistaken diagnosis of a suppurating lymph node. Thorough clinical assessment noting the absence of pain and the presence or history of a primary lesion coupled with aspiration cytology should avert the disaster of inappropriate incisional drainage. Management of cutaneous SCCs involves full clinical assessment of the tumour and draining lymph nodes aided by fine cut CT scanning if deep tissue or nodal involvement are suspected. Localised small lesions are cured by excision with clear surgical margins. Larger lesions may necessitate extensive surgical resection involving underlying tissues and a planned lymph node clearance. Elaborate reconstructive procedures may be necessary especially for areas of the face to restore function and attain acceptable cosmesis. Cutaneous SCCs are radio-sensitive. Radiotherapy as primary treatment, owing to its protracted treatment time, is reserved for small primary tumours in difficult anatomical sites. Radiotherapy is used as adjuvant therapy post-operatively in the management of advanced, infiltrative tumours, especially with multiple lymph node metastases or perineural tumour spread.
Cutaneous basal cell carcinoma
The most common site for BCC of the head and neck is the central face. The most common clinical variant is a translucent nodule made clinically more apparent by stretching the skin around the lesion. Most tumours run a slow protracted course and nodal metastases are rare. Tumours in areas of embryonal fusion lines may burrow deeply, making surgical clearance difficult. Local surgical excision is the usual form of treatment.
Salivary gland tumours
Salivary tissue is found not only in the three pairs of major salivary glands (the parotid, the submandibular and the sublingual glands) but also in small submucosal glands known as the minor salivary glands, which are scattered throughout the upper aerodigestive tract. The parotid glands are host to a variety of tumours both benign and malignant, primary and secondary.
The parotid glands, so named because of their anatomical proximity to the ear, are the largest salivary glands and produce a high volume of serous saliva. The most important anatomical relationship of the parotid gland is the facial nerve. This enters the posteromedial aspect of the gland as a single trunk and divides within its substance to emerge at the anterior border as the five main branches. In so doing, the facial nerve, for descriptive purposes, divides the gland into the larger superficial lobe covered by skin, platysma in part, and parotid fascia, and the smaller deep lobe, which lies in the parapharyngeal space and through which passes the posterior fascial vein and external carotid artery. Saliva drains from the gland via the parotid duct, which crosses the masseter muscle, and enters the buccal cavity opposite the upper second molar teeth.
The submandibular glands lie close to the inner aspect of the mandible lying on the mylohyoid muscle. The larger superficial lobe is covered by skin, platysma and deep cervical fascia, with the mandibular branch of the facial nerve on its way to supply the depressor anguli oris crossing its upper border. The posterior aspect of the submandibular gland is wrapped around the posterior-free border of the mylohyoid muscle, and the deep lobe of the gland passes forward deep to the mylohyoid lying on the hypoglossus muscle. The submandibular duct drains from the deep lobe, running a long course in the floor of the mouth to open at a papilla in the anterior floor of mouth just lateral to the lingual frenulum. The deep lobe of the gland and the duct are closely related to the lingual nerve, which may be involved in pathological processes and damaged during surgical treatment of the gland. The deep lobe is inferolaterally related to the mylohyoid and supramedially covered only by the oral mucosa in the floor of the mouth, thus being easily assessed clinically by bimanual palpation. Using the gloved left index finger placed in the floor of the mouth and the right fingers applied externally, submandibular glandular swelling may be differentiated from lymph node swellings.
The sublingual glands, predominantly mucussecreting, lie submucosally in the anterior floor of the mouth, supported by the mylohyoid muscles. These glands drain by multiple small ducts opening directly into the floor of the mouth along the sublingual folds.
Assessment of salivary gland disorders
The diagnosis of salivary pathology can be determined in a high proportion of cases by a thorough history, clinical examination and the judicious use of special tests.
A history of a slowly growing lump suggests a benign tumour. The rapid growth of a lump with the development of pain would strongly suggest a malignant process.
Clinical examination, including intra-oral and manual examination noting the site, size, shape, texture, tenderness, fixation, involvement of surrounding anatomical structures and the state of the regional lymph nodes, should not only define involvement of the salivary gland but also suggest the most likely pathological process. Deep lobe parotid masses may be detected by a diffuse bulge in the root of the soft palate or tonsillar fossa region and also may be palpable manually. Facial nerve function must be assessed with all parotid lesions. Tongue sensation should be tested in the presence of submandibular problems.
Computed tomography (CT) scans are useful to clarify anatomical detail in suspected malignant processes.
Magnetic resonance imaging
Magnetic resonance imaging (MRI) scans are indicated if cranial nerve involvement is suspected in malignant processes, especially those involving the parotid gland.
Fine-needle aspiration cytology
Cytological assessment of clinically suspected tumours of the salivary glands produces useful information in treatment planning. This is a safe procedure that is not associated with tumour dissemination or seeding.
The parotid gland is not only the commonest site of primary salivary neoplasms but is also affected by a wide variety of infiltrative and inflammatory processes. From a clinical point of view, it is easier to consider the presentation of either diffuse parotid swelling or a mass within the region of the parotid.
Any mass arising within the region of the parotid (i.e. from the zygomatic arch superiorly, the upper neck inferiorly, the anterior border of the masseter anteriorly and the mastoid process posteriorly) should be suspected as arising from within the parotid gland and treated accordingly. An isolated mass within the parotid is most commonly due to a parotid tumour. Eighty per cent of all salivary tumours occur within the parotid gland, and approximately 80% of parotid tumours are benign.
Pleomorphic adenoma (mixed salivary tumour)
Approximately 65–75% of mass lesions arising within the parotid gland are a benign, slowly growing, firm, smooth, usually asymptomatic tumour called pleomorphic adenoma. It is so named because of its histological appearance of a variable mix of glandular and stromal elements, both of which are thought to arise from myoepithelial cells. While the peak incidence is in the fifth decade with a slight female preponderance, this tumour can occur from childhood to old age. Malignant transformation is uncommon and rarely reported in those tumours present for less than 10 years' duration. While initially a smooth lump, with time multiple bosselations may develop. Rapid growth with pain and facial nerve involvement are the hallmark of advanced malignant change. Given the relentless growth pattern, the chance of malignant change and the inability to differentiate this benign tumour clinically from slow-growing malignant parotid tumours, all parotid tumours are best treated by complete surgical excision.
Usually no pre-operative investigation is necessary after establishing that the mass is mobile within the parotid gland. Cytology may help treatment planning by deciding the urgency and timing of surgery. Radiological assessment with CT scanning is only necessary when malignancy is suspected. Treatment consists of excision of the lesion with an intact capsule and preservation of the facial nerve. Incomplete excision or capsular rupture at the time of excision predisposes to local recurrence, which may be multinodular and exceedingly difficult to eradicate. Complete excision is associated with a very low local recurrence rate (usually <2%). The surgical technique involves identification of the main trunk of the facial nerve, which is then traced through the gland while the tumour with the surrounding parotid tissue is excised. This is known as a superficial parotidectomy. For deep tumours, the superficial lobe is excised first. The facial nerve and branches are then fully mobilised to allow removal of the deep lobe, either between or below the facial nerve. With careful surgical technique, the risk of permanent facial damage is low, but some degree of temporary facial weakness due to neuropraxia is not uncommon.
Adenolymphoma (Warthin's tumour)
Approximately 6–10% of parotid masses are due to a benign, softer tumour, more commonly found in males and arising in the inferior pole of the parotid, called an adenolymphoma. This tumour is so called because of the dense lymphocytic infiltration. The exact origin of this lesion is uncertain. Approximately 10% of cases are bilateral. The cytological picture is usually diagnostic. Surgical excision in the form of parotidectomy is usually recommended, except in the frail and elderly, in whom clinical observation may be more appropriate.
Malignant parotid tumour
Approximately 15–20% of parotid tumours are malignant. In Australia, the most common malignancy involving the parotid is metastatic squamous cell carcinoma from a skin primary arising in the head and neck region. Such tumours tend to spread to intraparotid lymph nodes. These lesions are often characterised by rapid growth due to tumour necrosis producing a cystic lesion within the parotid. Treatment of metastatic squamous cell carcinomas involve parotid resection, often in association with a neck dissection and post-operative radiotherapy. The parotid is uncommonly the site of metastases from other tumours, but kidney, thyroid, lung and breast cancers may all spread to the parotid and mimic primary parotid tumours.
PRIMARY PAROTID MALIGNANCIES
- Mucoepidermoid carcinomaThe most common primary malignancy of the parotid is mucoepidermoid carcinoma, which can occur from childhood onwards, with a peak incidence in the fifth to sixth decades. Approximately 75% of mucoepidermoid carcinomas are of low-grade histological type and present with a slowly growing parotid mass. High-grade tumours have a more rapid growth pattern and a poorer prognosis. Lymph node metastasis is uncommon.
- Adenoid cystic carcinomaAdenoid cystic carcinoma, formerly known as cylindromas, also present with a slowly growing asymptomatic parotid mass. These tumours are characterised by early perineural spread and have a propensity for late recurrence, often to bone or lung, even up to 20 years following an apparent cure.
- Acinic cell tumourAcinic cell tumour is another low-grade malignancy arising from the reserve cells of the terminal ducts and seen more commonly in females.
- Malignant pleomorphic adenomaMalignant pleomorphic adenoma is a more aggressive tumour that can arise either de novo or from a pre-existing pleomorphic tumour.
- AdenocarcinomaAdenocarcinoma, otherwise unspecified, may also arise in the parotid and displays a more aggressive growth pattern.
Treatment of malignant parotid tumours
Treatment decisions are based on the biological and histological features of the tumour. Slow-growing, clinically discrete, low-grade lesions are usually cured by complete surgical excision with sparing of the facial nerve. For those tumour demonstrating more aggressive histological features, parotidectomy with facial nerve sparing may be followed by radiotherapy. Clinically aggressive tumours with facial nerve involvement will require radical surgery with sacrifice of the facial nerve and radiotherapy. Primary nerve grafting using the sural nerve if possible is performed. Lymph node dissection is usually only performed for clinically or radiographically detected nodal metastasis.
Unlike the parotid gland, tumours of the submandibular gland are relatively uncommon. However, a higher proportion (approximately 40%) of submandibular tumours are malignant. Pleomorphic adenoma is the most common tumour affecting the gland. As with the parotid, most submandibular tumours present as a slowly growing asymptomatic lump. The diagnosis is usually suspected clinically and based on bimanual palpation. Differentiation from submandibular lymph node pathology can usually be confirmed by aspiration cytology. Submandibular tumours are treated by total gland excision. Malignant lesions with local spread beyond the submandibular gland may require sacrifice of the underlying lingual and hypoglossal nerves followed by radiotherapy to effect a cure.
Primary tumours of the sublingual gland are rare. Of those that do occur, 60% are malignant and only 40% are benign.
The extra-adrenal paraganglia of neural crest-derived cells can be the site of tumours known as paraganglionomas. These, usually benign, tumours may release neurotransmitters and produce intermittent hypertension and facial flushing. Tumours are named according to the neurovascular structure with which they are associated. The common sites for these uncommon tumours are the carotid body, the jugular bulb and the vagus nerve. Whilst most tumours occur sporadically, 10% represent an autosomal dominant inherited condition often associated with multiple paraganglionomas.
Carotid body tumour
The carotid body paraganglion is a chemoreceptor situated in the adventitia of the carotid bifurcation. Tumours present with a slowly growing, painless, smooth, firm, deep, lateral upper neck mass with limited superoinferior mobility. Transmitted pulsation may be evident but tumours, although vascular, are not truly pulsatile. The intense contrast enhancement on CT scanning with splaying of the carotid bifurcation and the typical clinical presentation are usually diagnostic. Surgical excision in the subadventitial plane with preservation of the carotid vessels is curative for benign small tumours. Occasionally vascular reconstruction may be necessary for excision of larger and malignant tumours.
Glomus jugulare tumours arise from the jugular bulb at the skull base. These deeply placed tumours are not clinically apparent until their growth impinges on surrounding cranial nerves IX, X, XI and XII or the internal auditory canal. Presenting symptoms include tinnitus, hearing loss, voice and swallowing problems. If bone erosion of the hypotympanum occurs a vascular mass may be clinically apparent medial to an intact tympanic membrane. A combination of contrastenhanced CT scanning and MRI should demonstrate the degree of bony erosion and the relationship of the tumour to the surrounding cranial nerves. The optimal treatment of these tumours is unresolved. Complete surgical excision with sparing of the facial and lower cranial nerves may be difficult to achieve. Post-surgical recurrent and persistent disease of 7% and 8%, respectively, are usually reported. Radiotherapy leading to tumour fibrosis produces similar imperfect results and carries its own morbidity.
Glomus Intravagale tumours arise from the paraganglionic tissue within the perineurium of the vagus nerve. These tumours are usually situated at the level of the inferior vagal ganglion. The usual clinical presentation is that of a neck mass near the origin of the sternocleidomastoid muscle with an associated vocal cord palsy. Multiple cranial nerve neuropathies may develop with progressive tumour growth. Contrast CT scanning demonstrates a vascular tumour within the carotid sheath displacing the vessel anteriorly. Other neural tumours of the vagus nerve form the differential diagnosis. Malignant transformation is commoner with glomus intravagale tumours than other parapharyngeal tumours with pulmonary metastases present in 20% of cases. Treatment consists of either radiotherapy or surgical excision based on an assessment of the tumour size and associated cranial nerve involvement. Although surgical resection necessitates sacrifice of the vagus nerve, more than 50% of the cases present with an established vocal cord paralysis.
50% of the solitary well encapsulated tumours arising from the schwann cells of peripheral nerve sheaths occur within the head and neck. Within the head and neck the common nerves of origin are the acoustic nerve and vagus nerve and less commonly from VII, IX, XI and XII. These tumours expand the nerve from which they arise and surgical excision with preservation of the nerve can occasionally be achieved. The clinical presentation is of a slow-growing, painless, lateral neck mass with limited mobility. Neurological signs suggesting the nerve of origin are unusual. Radiological examination demonstrates a well-circumscribed mass with some but not marked contrast enhancement. MRI may demonstrate an associated neural structure suggesting the diagnosis. Tumours arising from a cervical nerve root may extend through the intervertebral foramen, producing a dumb bell tumour with a cervical and spinal component. Aspiration cytology with its benign spindle cell pattern is usually inconclusive. Treatment is determined by tumour extent and the clinical picture. Slow-growing, small tumours in elderly patients may be observed. Tumours arising peripherally in the neck may be separated from the associated nerve with minimal morbidity. Surgical excision of large tumours or those in surgically less accessible sites or contiguous with important neurological structures such as the brachial plexus is associated with the risk of significant neurological morbidity.
Less than 5% of schwannonas are malignant. These tumours infiltrate locally, may extend intracranially or intravertebrally and can metastasise to the lungs. Aggressive surgical resection is advocated.
Neurofibromas are tumours arising from the peripheral nerve sheaths and present commonly as rubbery, fusiform subcutaneous nodules. Multiple neurofibromas and plexiform neurofibromas are found along with café au lait spots, skeletal, C.N.S. and ocular lesions in the autosomal dominant inherited disorder of neurofibromatosis. Surgical excision, with sacrifice of the associated nerve is definitive treatment for isolated lesions.
Soft tissue sarcomas
Soft tissue sarcomas are tumours of mesenchymal origin that display a wide spectrum of clinical and biological behaviour. Less than 10% of these uncommon tumours arise in the head and neck. A number of genetic abnormalities have been identified. Many of these clonal abberations have the potential to be applied to the differential diagnosis, in these, often difficult to categorise, tumours. Most tumours present as a painless neck mass. Tumours arising from the tissues of the upper aerodigestive tract or the deep tissue spaces may present with a variety of symptoms such as epistaxis, otalgia, visual disturbance or cranial nerve palsies resulting from local tumour infiltration. A thorough clinical examination including intra-oral, neurological and endoscopic examination of the upper aerodigestive tract often forms an impression of the extent of the tumour. High quality CT scanning and MRI allow accurate anatomical assessment. Fine needle aspiration cytology is simple and safe for accessible tumour and is helpful in differentiating sarcomas from other more common tumours but is usually unhelpful in the precise diagnosis of tumour type and grade. Core needle biopsies, radiologically directed, usually provide adequate tissue for pathological assessment. Tumours are staged according to their size, whether superficial or deep and histological grading based on differentiation, cellularity, density of the stroma, vascularity and the degree of necrosis.
Malignant fibrous histiocytoma (MFH)
MFH is the commonest soft tissue sarcoma in adult. Less than3%involve the head and neck, with the upper aerodigetive tract being favoured and less commonly neck and salivary glands. Five-year survival for these aggressive tumours is approximately 50%.
Dermatofibrosarcoma Protuberans, which accounts for approximately 7–15% of soft tissue sarcomas, usually presents as an elevated, firm, solitary, slowly growing, painless mass in the scalp or neck. Metastases are uncommon and an excellent outcome is achieved if histologically clear margins are obtained following local excision.
Over half of all angiosarcomas present as an ulcerating, nodular or diffuse dermal lesion of the scalp or face in elderly white males. They are uncommon tumours, accounting for only 0.1% of all head and neck tumours.
Rhabdomyosarcoma is the most common paediatric soft tissue sarcoma. This malignant tumour of striated muscle cell origin arises in the nasal cavity, paranasal sinuses, orbit, nasopharynx and middle ear. Early metastases both regional and distant are common. Treatment usually involves chemotherapy and irradiation with an overall survival of approximately 50%.
Bone tumours may affect the mandible, maxilla or cervical vertebrae, presenting usually as painless swellings. Tumours are classified according to the matrix produced by the tumour cells into condro sarcomas if cartilagenous, osteo sarcomas if osteoid and fibro sarcomas if they lack a distinct matrix. Surgical excision with clear margins is associated with survival rates of 40–80% independent of the anatomical sites of origin. Distant metastases are infrequent.