Imaging of Submandibular Gland Tumours and Cancers

A minority of submandibular tumours require imaging

Indications

Suspected non-neoplastic disease e.g. sialadenitis, sialolithiasis (US / CT)
Distinguish between submandibular lymph node and salivary mass (US)
Reduced mobility/fixed tumour with invasion of surrounding structures (Panorex / CT / MRI)
Neurological deficits to determine extent of perineural invasion (MRI with Gd)
Malignant tumour (clinically / cytologically) to exclude cervical metastases (US / CT)
Exclude lung metastases with suspected/known malignancy (CXR / CT)

Panorex: For adherence to mandible

Ultrasound

Sialolithiasis / chronic sialadenitis / neoplasm
Cystic vs solid
Cervical lymph nodes
Advanced tumours: Erosion of mandible / invasion of muscles of floor of mouth / tongue

MRI

Advanced tumours: Erosion of mandible / invasion of muscles of floor of mouth or tongue (Good soft tissue differentiation)
Perineural invasion

PET-CT: Unhelpful as benign pathology (pleomorphic adenoma, infection), lymphoma are PET-avid