6. Head and Neck p334-344 (Soft Tissue Neck) Flashcards
Parotid space (6)
Basically the parotid gland and portions of the facial nerve.
Can’t see facial nerve, but can see the retromandibular vein which runs medial to the facial nerve.
Parotid is the only saliary gland to have lymph nodes, so pathology of the gland itself or lymph nodes is possible.
Contains
- Parotid gland
- Facial nerve
- Retromandibular vein
Pleomorphic adenoma (4)
Most common major (and minor) salivary gland tumour. Most commonly occurs in the parotid (can occur in submandubilar or sublingual glands).
90% occur in the superficial lobe.
Commonly T2 bright with rim of low signal.
Small malignant potential and are treated surgically.
Superficial vs deep pleomorphic adenoma (4)
Involvement of the superficial (lateral to the facial nerve) or deep (medial to the facial nerve) is important for surgical approach.
Line is drawn connecting the lateral surface of posterior belly of digastric muscle, with the lateral surface of the mandibular ascending ramus, to separate superficial from deep.
Can spill and reoccur if not removed properly.
Warthins tumour (3)
Second commonest benign tumour, only occurs in the parotid gland.
Usually cystic, in a male, 15% bilateral, associated with smoking.
Takes up pertechnate, and is basically the only parotid tumour to do so.
Mucoepidermoid carcinoma (4)
Most common malignant tumour of the minor salivary glands.
Smaller the gland, the more common the malignant tumours and the bigger the gland, the more common the benign tumours.
Variable appearance based on histologic grade.
Associated with radiation
Adenoid cystic carcinoma (2)
Malignant salivary gland tumour, favours minor glands but can affect the parotid.
Common for perineural spread.
Lymphoma (4)
Can get primary or secondary. Only occurs in the parotid because it’s the only salivary gland with lymph nodes.
If bilateral, think Sjogrens.
Sjogrens have massively elevated risk of parotid lymphoma.
Appearance is variable, like other lymphomas.
Acute parotitis (5)
Obstruction of flow of secretions is commonest cause.
Likely due to stone in Stensen’s duct, which will become dilated.
Stones are calcium phsophate.
Post infectious parotitis is usually bacterial.
Mumps is commonest viral cause.
Sialography is contraindicated in the acute setting.
Benign lymphoepithelial disease (3)
Bilateral mixed solid and cystic lesions with diffusely enlarged parotid glands.
Seen in HIV
Painless, unlike parotitis.
Sjogrens (5)
Autoimmune lymphocyte induced destruction of the gland.
“Dry eyes and dry mouth”
Typically women in their 60s.
Hugely (1000x) increased risk of non-hodgkins MALT type lymphoma.
Honeycombed appearance of the gland.
Carotid space (4)
Contains:
- Carotid artery
- Jugular vein
- Portions of CN 9, 10, 11
- Internal jugular chain lymph nodes.
Carotid space tumours - DDx (4)
Paraganglioma
Schwannoma
Neurofibroma
Lymph nodes: mets from SCC frequently affect this area
Paragangliomas (7)
3 different types, based on location, with similar imaging features.
Hypervascular (intense tumour blush) with salt and pepper appearance on MRI from heterogeneity and flow voids.
Can be multiple or bilateral in familial conditions.
111In Octreotide accumulates in these tumours
Locations/types:
Carotid body tumour - at the carotid bifurcation, splaying the ICA and ECA
Glomus vagale - above carotid bifurccation, below jugular foramen.
Glomus jugulare - skull base, often destroys jugular foramen and/or middle ear
Glomus tympanicum - confined to middle ear. “overlying the cochlear promontory. Middle ear is intact
Schwannoma (5)
Can involve 9th, 10th, 11th and even 12th cranial nerves.
Not very vascular (unlike paraganglioma)
No salt and pepper on MRI (unlike paraganglioma)
Not 111In-octreotide avid (unlike paraganglioma)
No flow voids (unlike paraganglioma)
Lemierre syndrome (4)
Thrombophlebitis of the jugular veins with distant metastatic sepsis, usually septic emboli in the lung.
Found in setting of oropharyngeal infection (pharyngitis, tonsillitis, Peritonsillar abscess) or recent ENT surgery
Caused by Fusibacterium Necrophorum
Masticator space (3)
Contains muscles of mastication (masticator, temporalis, medial and lateral pterygoids)
Angle and ramus of mandible and inferior alveolar nerve.
This space extends superiorly along the side of the skull, via temporalis muscle. Aggressive neoplasm or infection may ride up here
Odontogenic infection (3)
Most common cause of masticator space mass in adult.
Should look at mandible on bone windows next.
Look for spread via pterygopalatine fossa to orbital apex and cavernous sinus.
Sarcomas (2)
Can get rhabdomyosarcomas in the masticator space in kids.
Also sarcomas from the mandible (chondrosarcoma favours the TMJ)
Cavernous haemangiomas (3)
Identified by presence of phleboliths.
Venous or lymphatic malformations may involve multiple compartments/spaces.
Congenital pathology and aggressive infection/cancer tends to be trans-spacial.
Perineural spread (3)
Spread from head and neck primary along the 5th cranial nerve.
Occurs classically in:
- adenoid cystic minor salivary tumours
- melanoma
Nerve sheath tumours (2)
Schwannoma or neurofibroma of V3 in the masticator space.
Schwannoma is more likely to cause foramina expansion vs perineural tumour spread.
Retropharyngeal space/danger space (3)
Behind the middle layer of the deep cervical fascia, but anterior to the alar fascia.
Danger space is actually just posterior to the “true” retropharyngeal space, behind the layer of alar fascia.
It’s a potential space, can’t see unless it’s distended.
Infection in the danger space tracts down into the mediastinum, so pus (or cancer) can get right into the mediastinum.
Retropharyngeal space/danger space infection (3)
Involvement of the retropharyngeal space most often occurs from spread from the tonsillar tissue.
Enhancing soft tissue and stranding in the space.
Should evaluate for spread of infection into the mediastinum.
Necrotic nodes/squamous cell mets in the retropharyngeal/danger space (3)
SCC mets or suppurative infection to the lateral retropharyngeal nodes of Rouviere.
Papillary thyroid cancer can also met here.
Lymphoma can involve these nodes, but won’t be necrotic until treated.
