96 Sinonasal Tumours
Tumours of the nasal cavity and sinuses are rare and may be benign or malignant. Because of the hidden nature of the nasal cavities and sinuses, a high index of suspicion is required to avoid delay in diagnosis. This chapter addresses the key issues of sinonasal tumours and highlights their characteristics, management and outcomes.
96.1 Clinical Presentation
96.1.1 Benign Nasal Tumours
Benign nasal tumours often present as a unilateral nasal polyp. The usual symptoms are as follows:
• Nasal obstruction. This is generally unilateral unless a tumour fills the area of the nasopharynx.
• Epistaxis. Spontaneous bleeding is not usual but is usually induced by forceful nose blowing.
• Anosmia. Loss of the sense of smell may be associated with obstruction to airflow reaching the olfactory cleft.
Occasionally, a benign tumour may obstruct the sinus ostium and lead to a complication such as a mucocele, a mucopyocele and orbital swelling.
96.1.2 Malignant Nasal Tumours
Malignant tumours similarly cause a mass effect and obstruct the nasal airway. They can therefore also present with nasal obstruction. Loss of sense of smell may also arise from obstruction of airflow to the olfactory clefts but can also be due to direct involvement of olfactory mucosa by the tumour.
The cardinal symptoms of a malignant sinonasal tumour are a unilateral bloodstained nasal mucus discharge and facial pain.
Malignant tumours can also invade local tissues and induce secondary problems according to the direction of spread (Table 96.1). Metastasis to regional cervical lymph nodes and distant spread may also cause symptoms and signs and should always be considered.
96.2 Initial Clinical Management
Any patient presenting with unusual sinonasal symptoms and signs or a unilateral polyp or mass within the nose should undergo a thorough endoscopic assessment of the nasal cavities after suitable vasoconstriction.
Table 96.1 Local effects of sinonasal tumours
Relative to nasal cavity
Otitis media with effusion
Spread across midline
Anterior skull base
Invasion into intracranial cavity
Spread to oral cavity
A multi-planar computed tomography (CT) scan of the sinuses should be considered and obtained. Should there be any possibility of the tumour mass being malignant, an urgent enhanced magnetic resonance imaging (MRI) scan should be arranged.
It is difficult to predict the histological nature of a nasal polyp/mass on clinical grounds alone, and attention should be given to histological confirmation. A biopsy should be deferred until after any imaging While it may be possible to obtain a biopsy in clinic, the risk of inducing significant bleeding should be considered. Ideally, the patient should be admitted urgently for assessment under general anaesthesia. The surgeon can then either simply take a diagnostic biopsy or choose to debulk and possibly resect the mass, as long as this does not induce severe haemorrhage or compromise further treatment.
Once the histology is known, all patients with malignant tumours should then be presented for discussion at the local head and neck or skull base multi-disciplinary team (MDT) meeting.
Further scans may be required, according to the agreed MDT protocol. These are likely to include MRI of the neck and CT of the chest, abdomen and pelvis.
96.3 Specific Benign Sinonasal Tumours
96.3.1 Sinonasal Papilloma
Sinonasal papillomas are the commonest sinonasal tumour, (0.5–4% of all sinonasal tumours) and the estimated incidence is 1/1,000,000/year. They are more common in men and the peak age at presentation is the fifth to sixth decade.
The term sinonasal papilloma encompasses exophytic, inverted and oncocytic papillomas.
a. Exophytic papilloma
These present as warty-looking growths in the anterior nasal cavity, particularly on the nasal septum. The lesions may be multiple and may spread to other regions within the nasal cavity. They are virally related and have a propensity for recurrence, even if completely excised. They do not carry any risk of malignant transformation. However, it should be noted that the histology can be confused with well-differentiated squamous cell carcinoma.
b. Inverted papilloma
The inverted papilloma derives its name from the pattern of cell growth as seen histologically. In practice, there may be areas of exophytic growth as well.
The endoscopic appearance can be variable and range from a smooth, pale and lobulated polypoid lesion to a dusky red, irregular tumour. Generally, they are quite large at the time of diagnosis unless they have been found as an incidental finding in patients presenting with chronic rhinosinusitis.
About half of these tumours arise from the maxillary sinus. The rest arise from the ethmoid/nasal cavity and a smaller number occur in the frontal sinus and sphenoid. Tumours that affect the frontal sinus have nearly always originated in the anterior ethmoid and encroached into the frontal sinus through the natural ostium.
The tumour characteristically causes focal hyperostosis that is evident on the CT scan (Fig. 96.1). The preferred staging system is that described by Krouse (Table. 96.2).
Most tumours can be completely removed endoscopically, even if this includes extended endoscopic techniques into the maxillary, frontal and sphenoid sinuses. External surgery is now limited to extensive tumours affecting the extremes of the frontal sinus and maxillary sinus.
Fig. 96.1 Coronal CT scan showing hyperostosis in the lateral wall of the right maxillary sinus secondary to inverted papilloma.
Table 96.2 The melanoma seven-point checklist lesion system
Tumour confined to the nasal cavity
Tumour confined to the ethmoid sinus and medial/superior portion of the maxillary sinus
Tumour involving the lateral or inferior portions of the maxillary sinus/or frontal sinus/or sphenoid sinus
Tumour extending beyond the nose and paranasal sinus boundaries or malignant disease
Source: Krouse JH; Laryngoscope, 2000; 110(6): 965–968
The tumour may sometimes behave aggressively and cause bone erosion. There is a small but significant risk of malignant transformation, estimated to be less than 2%. There is a significant risk of local recurrence of approximately 20%. The risk of recurrence is decreased by cleaning the bone adjacent to the tumour origin with a diamond drill, endoscopic-targeted tumour base surgery and taking frozen sections of the tumour margins.
Following tumour removal, the patient should be reviewed and assessed for tumour recurrence regularly for up to 5 years.
The oncocytic papilloma is the least common variety of sinonasal papilloma and behaves very similarly to inverted papilloma. The name is derived from the histological features of cylindrical oncocytic cells within the tumour.