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.
