Neck and associated structures Flashcards
List some cystic masses of the neck
Thyroglossal duct cysts branchial cleft cyst abscess/cellulitis Laryngocele lymphangioma dermoid cyst Sebaceous cyst
Describe a thyroglossal duct cyst
Most common developmental cysts in the neck
Develops from epithlelial lined remnants of embryonic thyroglossal duct
Can appear from the base of tongue to suprasternal region
Most lie between hyoid bone and thyroid cartilage with infrahyoid strap m. over the edge of cyst
A sinus may be present
Cyst development and enlargement are in response to repeated local infection and inflammation
Usually midline or slightly to one side
Move superiorly with swallowing
Rarely develops into malignancy
Common in children and young adults
Usually painless
What are the different locations for a thyroglossal duct cyst?
Most cysts are found either in the anterior neck just inferior to the hyoid bone or under the tongue. May also be found in front of the thyroid cartilage or the foramen cecum
What is the ultrasound appearance of a thyroglossal duct cyst?
Classic appearance noted in less than half of cases and includes a thin-walled, anechoic unilocular cyst.
Typically, however, these cysts are caused by high protein content rather than inflammation so they are hypoechoic or heterogeneous, some appearing pseudosolid and mimicking ectopic tissue.
Describe a branchial cleft cyst
Second most common head and neck lesion in children after thyroiglossal duct cyst
Mostly devlop from the 2nd branchial cleft
Typically positioned laterally in the neck near the:
angle of the mandible
Under the anterior margin of the SCM muscle
Superficial to the CCA and IJV
Sinus tract may occur (just above clavicle, external auditory canal or tonsillar fossa)
Lymphoid tissue lining the cyst hypertrophies during an URTI
Makes branchial cleft cyst most present
Post-traumatic incident is another case for presentation
Most common in children and young adults
Unilocular and well-defined
Beak may be seen
Anechoic with posterior enhancement to diffuse low-level echoes/debris with little posterior enhancement
Typical ultrasound appearance of a branchial cleft cyst
On sonography, branchial malformations typically appear as a simple or complex cyst with through transmission. These lesions are susceptible to hemorrhage or superimposed infection
What are some non cystic masses of the neck?
Lipoma, masseter muscle pathology, neural masses, vascular lesions
List some masseter muscle pathology
Abscess
Tumour (mets from lung, breast or melanoma)
Haemangioma
Muscle hypertrophy (thickened, unilateral)
List some neural masses
Schwannoma or neurofibroma
Paraganglioma
Carotid body tumour
List some vascular lesions
Carotid artery bulb
Jugular vein thrombosis
Comment of the shape of normal/reactive and malignant cervical nodes
Most normal or reactive cervical lymph nodes have flattened, elongated, oval shape with length/width ratio >2
Malignant nodes tend to be round, length/width ratio <1.5 suggest malignancy
Comment on the ultrasound appearance of cervical nodes
Normal or reactive nodes are usually hypoechoic compared to thyroid with fatty hilum
Malignant nodes can be hypoechoic to isoechoic with obliterated fatty hilum
Can take on features of the primary
Variable blood flow
Look for extranodal infiltration
May have undergone necrosis and appear cystic
Optimise colour and power to assess for slow flow (very important)
Lymph node hypertrophy may be due to bacterial or viral causes
Children can have infections of one lymph node
Common for nodes to become inflammed to remain enlarged after inflammation disappears due to fibrosis
What are the vascular features in normal or reactive cervical nodes
no flow (due to the low flow velocity or low number of red blood cells ) or a few intranodal dots; and hilar flow with or without peripheral branches from the longitudinal hilar vessels.
What are the vascular features in malignant cervical nodes
displacement of the hilar vessels; aberrant vessels; missing intranodal flow signals; sub-capsular or peripheral flow; and chaotic flow patterns of the Doppler traces;
List the salivary glands
Parotid, submandibular, sublingual glands
What is the normal ultrasound appearance of the salivary glands?
Parotid has Slightly greater echogenicity compared to submandibular
Homogeneous with mid level echoes
Hypoechoic blood vessels
Non-dilated ducts are thin echogenic line within superficial portions of the glands
Intraglandular ducts are short, echogenic lines
Intraparotid nodes often seen
5mm diameter with echogenic hilum
Facial nerve not usually seen
Retromandibular vein runs close to parotid gland
What are the important questions to ask before scanning a patient?
Does a lump appear, become painful or increase in size after eating?
Generally, salivary duct obstruction causes the gland to increase in size with eating and this resolves slowly over about an hour. Tumours do not enlarge during salivation, but do tend to get bigger with time. Lemon juice or an acid-drop may be used to test this.)
Have you had any recent contact with mumps?
Do you have any dryness in the mouth?
Persistent dryness suggests diffuse salivary gland disease. Obstruction to even two major ducts produces little apparent change in saliva production
Any facial weakness?
Facial weakness may infer parotid gland infiltration.
What are some things to consider when scanning the salivary glands?
Is the mass within the gland or extraglandular?
Is the mass solitary? Are there multiple masses?
Is it superficial or deep? (as this may determine the surgical approach)
What is the echogenicity of the mass compared to the normal glandular tissue? Is it solid/cystic/mixed?
Are the borders well defined or irregular?
Have you seen the complete boundaries if the mass is large?
Is there any regional lymphadenopathy and does it extend beyond the local region?
What can cause aacute/chronic sialadentitis?
due to viral, bacterial or autoimmune causes.
predisposing factors include duct obstruction, dehydration, debilitation and immunosuppression that reduce salivary secretions.
What are the ultrasound appearances of acute/chronic sialadentitis?
affected salivary glands will be enlarged and hypoechoic.
parenchyma will be heterogenous (this may be due to microabscesses, duct dilatation and/or retention cysts).
Abscess formation may follow (supporative sialadenitis) , ill-defined hypoechoic mass, frank fluid may be detected and hyperechoic foci due to gas bubbles.
There is no mass effect
Ultrasound-guided abscess drainage may be useful to aid treatment.
Describe the occurence of acute viral inflammation of the salivary glands
usually due to mumps (sometimes mononucleosis, and cytomegalovirus (CMV))
commonly affecting the parotid glands and may be uni- or bilateral.
important to exclude abscess formation.
may progress to chronic sialadenitis.
causing painful unilateral or bilateral swelling.
In children, viral salivary gland infections are the most common cause of acute inflammation.
What is the ultrasound appearance of acute viral inflammation of the salivary glands?
affected gland will exhibit enlargement with an hypoechoic appearance.
diffusely enlarged gland that may have a normal, heterogeneous and/or hypoechoic echotexture with increased vascularity.
Frequently there is bilateral involvement, although unilateral involvement may be seen in up to one-third of patients.
What is the pathphysiology of juvenile (recurrent) parotitis?
most common cause of childhood parotid swelling in developed countries
manifests with intermittent pain, fever, and unilateral or bilateral parotid swelling
submandibular and sublingual glands are not affected
no known cause for the recurrent parotitis.
Differential diagnosis mumps or suppurative parotitis, which is excluded by lack of pus from the parotid duct.
Age 3 to 6 years ceases near puberty or in late adolescence.
What is the ultrasound appearance of juvenile (recurrent) parotitis?
enlarged parotid glands
multiple round, hypoechoic areas measuring 2 to 4 mm in diameter, likely representing peripheral sialectasis and lymphocytic infiltration
may be hypervascular, secondary to acute inflammation.
What is the pathophysiology of chronic sialadentitis?
caused by an inflammatory process that damages the acini
altering the drainage system of the gland
etiology may be infectious or noninfectious.
Patient presentation:
gland swelling and pain, particularly postprandial.
What is the ultrasound appearance of chronic sialadenitis?
heterogeneous gland
small, punctate, echogenic areas or with multiple hypoechoic areas
Punctate areas are believed to represent mucus in the dilated ducts or walls of the dilated ducts. The hypoechoic areas likely represent edema and sialectasis.
Increased vascularity can be demonstrated in areas of abnormal echotexture.
Findings may be bilateral and associated with intraglandular or adjacent lymph node involvement.
What is sialectasis?
This is dilatation of the tertiary intraglandular ducts.
Sialography may be more useful than ultrasound for this condition, but it may help exclude others.
What is the pathophysiology of sjorgren syndrome?
common auto-immune related disease affecting the salivary and lacrimal glands.
Almost affects only women who present with dry eyes and mouth, glandular enlargement and reduced secretions.
patients are usually monitored with ultrasound because of increased risk for lymphoma.
What is the ultrasound appearance of Sjogren syndrome?
early stages, the gland may have a normal texture with or without diffuse enlargement.
Later stages have multiple cystic lesions within an inhomogeneous, hypoechoic, hypervascularised gland.
Chronic disease may cause the gland to reduce in size.
difficult to determine with ultrasound imaging.
What is the pathophysiology of sarcoidosis in the salivary glands?
Rare
usually affects the submandibular gland.
patient presents with a lump, with or without pain.
idiopathic granulomatous disease that is uncommon in children
Parotid involvement, noted in 30% of patients, may be the only initial finding.
What is the ultrasound appearance of sarcoidosis in the salivary glands?
A diffusely hypoechoic gland of normal or increased size.
How does post radiotherapy of the neck often present?
This may often cause localised pain and swelling of the salivary glands, especially the submandibular.
What is the ultrasound appearance of post radiotherapy of the neck?
In the acute phase, there will be increased gland size with an hypoechoic appearance.
In the chronic phase, you may find a small, atrophied and hypoechoic gland.
Discuss sialosis
Non-tender, recurrent enlargement of the parotid gland
Gland hypertrophy and subsequent fatty infiltration
Commonly occurs in malnutrition, alcholism, diabetes
Enlarged, echogenic gland with fine texture
Describe ranula cysts of the salivary glands
Mucous retention cyst of the sublingual and minor salivary glands
Simple ranula most common
Simple ranula may rupture into submandibular space, forming a pseudocyst
Diving/plunging ranula- extends below mylohyoid
Pathophysiology of abscess/cellulitis of the salivary glands
Most common in immuno-suppressed patients
Maybe as a consequence of suppurative adenopathy, salivary gland infection, dental abscess, post radiotherapy
Ill-defined irregular collection with thick wall and internal debris
u/s assisted drainage
May appear as loss of fascial planes and associated inflmmatory cervical lymphadenopathy
Pathophysiology of laryngocele
Rare
Cystic mass/sac in the larynx
Associated with laryngeal tumours
Associated with regular forced expiration eg. woodwind instruments
Pathophysiology of dermoid cyst
Rare
Midline or slighly off midline in sublingual or submental region of the neck
Well-circumscribed and echogenic mass
Ultrasound appearance of sebaceous neck cyst
Common in posterior neck
Well-circumscribed with well defined anechoic or low internal level echoes
Posterior enhancement
What are some results of trauma to the salivary glands?
Parotid gland due to anterior, superficial portion of gland
Haematoma
Fistula
Sialocele
Describe salivary gland calculi
Sialolithiasis within the gland Sialodocholithiasis within the duct Involves submandibular gland Submandibular saliva has greater mucous content than parotid Single or multiple Can be radiopaque
What are some causes of ductal obstruction?
When dilated, easily seen
May be due to calculi, tumour or stricture
Dilated duct >2mm
What are the common presentations of tumours in the salivary glands?
Palpable mass
More common in parotid gland
Likely benign
In submandibular and sublingual glands, greater chance of being malignant
Mass in children likely to be malignant
Tumour in parotid may be lymph node related
Malignant nodes more common than malignant tumours
Malignant tumours present as hard mass, facial nerve paralysis and cervical lymphadenopathy
Biopsy required
What is the most common salivary gland tumour?
Benign Pleomorphic adenoma
Describe a benign pleomorphic adenoma
Mixed salivary tumour Most common salivary gland tumour Slow-growing, smooth, non-tender Malignant change- rapid growth Hypoechoic, homogenerous mass with lobulated sharply marginated borders
What is the second most common tumour of the parotid gland?
Warthin tumour
Describe a warthin tumour
Second most common benign tumour of parotid
Multiple and bilateral
Originates within intraparotid lymph nodes
Slow growing
Smoot swelling
Well-circumscribed hypoechoic mass, may be heterogeneous
Describe a malignant tumour of the salivary glands
Hypoechoic
Small, well-circumscribed, some may be ill-defined
Larger tumours are heterogeneous due to necrosis and hemorrhage with ill-defined margins
Disorganised flow with high resistive spectral trace
What is the most common malignant tumour of the salivary glands?
Mucoepidermoid tumour
Describe a Mucoepidermoid tumour
Most common malignant salivary tumour
Occurs at any change
Common in children
painless swelling, with or without facial nerve involvement
well-circumscribed hypoechoic lesion, with a partial or completely cystic appearance.
What is another very common salivary tumour
Cylindroma
Describe a cylindroma
One of the most common malignant tumour of salivary gland
Usually affects salivary glands more than parotid
Most common in submandibular
May infiltrate facial nerve
Single, rounded, hypoechoic mass
Name some other malignant salivary gland tumours
Adenocarcinoma
Malignant pleomorphic adenomata
Lymphoma and primary non-Hodgkins lymphoma usually affect parotid glands and surrounding nodes
Metastatic tumour (squamous cell carcinoma of the skin, malignant melanoma, non-Hodgkin’s lymphoma)
