What Does This CT Scan Regarding Severe Headache And Painful Cheeks Indicate?

Having cheek pain and severe headaches on left side for approx. 3 months. Waiting to see an ENT and just had a CT Scan with the following results: Curvilinear soft tissue thickening is seen along the posterior wall of the left maxillary sinus. The soft tissue is lobulated measuring 1.4cm in AP by 2.0cm in transverse by 3.9cm in craniocaudal dimensions. It appears somewhat lobulated and shows a soft tissue density. No evidence of associated cystic change or calcifications. There is associated smooth erosion of the postermedial and posterlateral wall of the maxillary sinus as well as the base of the pterygoid plate. Impression: Soft tissue lesion in the posterior aspect of the left maxillary sinus with evidence of associated bony erosion as described above. This may represent evidence of more aggressive sinusitis, possibly fungal in nature. Malignancy considered less likely, but not entirely excluded. ENT consultation is advised. How serious is this condition? Thanks