Skull Base Condition (Sinonasal malignancy)

What is Sinonasal malignancy?

This term describes a diverse group of malignant tumours affecting the nose and sinus system. SCC account for 70% of sinonasal malignancy, adenocarcinoma 10% and adenoid cystic carcinoma 10%.
Nickel workers are at risk of developing SCC, woodworkers are at risk of adenocarcinoma. This is often delayed up to 20 years after exposure. The prognosis is poor with less than 50% of patients surviving for 5 years.

Common sites for sinonasal malignancy are:
-Maxillary sinus
-Nasal cavity
-Ethmoid sinus

Presentation
Some or all of the following features may be seen:
-Nasal obstruction
-Epistaxis
-Sinusitis
-Maxillary symptoms
-Loose teeth
-Ulcer on palate
-Cheek swelling
-Ethmoid symptoms
-Unilateral obstruction
-Diplopia
-Headache.

Investigations
-CT and/or MRI
-Endoscopy and biopsy
-FNA if cervical metastases

Treatment
Surgical resection and/or radiotherapy may be required. Treatment decisions should be made by an MDT in a specialist head and neck clinic taking into account the type of tumour and the staging.

TNM Staging of sinonasal malignancy
Maxillary sinus
-T1-Tumour limited to antral mucosa.
-T2-Tumour causing erosion or destruction into hard plate/lateral nasal wall.
-T3-Tumour eroding posterior wall/subcutaneous/cheek/medial orbit
-T4-Intracranial extension/orbital apex/skin of nose.

Ethmoid sinus
-T1-Confined to ethmoid
-T2-Extends to nasal cavity
-T3-Extemds to anterior orbit/maxillary sinus.
-T4-Intracranial extension