How would you improve the scanning of small lesions?
- Use light pressure
- Thick layer of gel
- Gel standoff
- Mobilise mass with fingers
Describe a thyroglossal duct cyst
A thyroglossal duct cyst is the most common developmental cyst in the neck. It develops from epithelial lined remnants of the embryonic thyroglossal duct. They can appear between the base of the tongue and the suprasternal region, most lying between the hyoid bone and thyroid cartilage. Cyst development and enlargement are in response to repeated local infection and inflammation. They are usually in the midline or slightly off centre and move superiorly with swallowing. Patients usually present with no pain.
Describe the U/S appearance of a thyroglossal duct cyst
- Well-circumscribed mass of 2-4cm with variable appearance dependent on level of infection, number of episodes
- Anechoic with posterior enhancement
- Homogeneously hypoechoic with fine internal echoes
- complex with coarse, irregular internal echoes and septae
- Solid with little to no posterior enhancement
- Debris due to viscosity of fluid, infection of haemorrhage
Describe a branchial cleft cyst
Most branchial cleft cysts develop from the 2nd branchial cleft. They are typically positioned laterally near the angle of mandible, under the anterior margin of the sternocleidomastoid muscle, superficial to the CCA and IJV. Sinus tracts may occur. Two common presentations are after an URTI or post-traumatic incident.
Describe the U/S appearance of a branchial cleft cyst
- unilocular and well defined
- a beak may be seen
- anechoic with posterior enhancement
- diffuse low-level echoes/debris with little posterior enhancement
Describe an abscess/cellulitis
- 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 be required
- May appear as loss of fascial planes and associated inflammatory cervical lymphadenopathy
Describe a laryngocele
- Rare
- Cystic mas/sac in the larynx
- Associated with laryngeal tumours
- Associated with regular forced expiration eg. woodwind player
Describe a lymphangioma/cystic hygroma
- Neonates/young children
- Cystic masses with thin internal septae supero-laterally in the neck
Describe a dermoid cyst
- rare
- midline, slightly off midline in sublingual or submental region of the neck
- well-circumscribed and echogenic mass
Describe a sebaceous cyst
- common in the posterior neck
- well circumscribed with well defined anechoic or low level internal echoes
- posterior enhancement
Describe a lipoma
- benign
- encapsulated lesions that are often palpable
- commonly occur int he superficial tissues of the head and neck
- tend to displace adjacent structures rather than infiltrate
- compressible, well-defined and usually elliptical
- hyperechoic mass compared to adjacent muscle
- heterogeneous internal echoes with linear stranding
- no posterior enhancement or shadowing with no significant vascularity
List types of masseter muscle pathology
- abscess
- tumour
- haemangioma
- muscle hypertrophy
Describe schwannoma and neurofibromas
- hypoechoic
- heterogeneous solid mass with posterior enhancement
- well-defined (benign)
- ill defined can indicate malignant change
- adjacent nerve may be thickened
- schwannomas are normally more vascular than neurofibromas
Describe paraganglioma/chemodactomas
- arise from neural crest cells of the vessel walls
Describe carotid body tumours
- Rare
- present as a pulsatile, painless mass in the anterior triangle, near the angle of the mandible
- may be bilateral
- associated with other head paragangliomas
- located at the common carotid bifurcation and splays the internal and external carotid arteries
Describe the U/S appearance of carotid body tumours
- Well defined
- hypoechoic compared to adjacent structures
- solid
- does not calcify
- variable internal vascularity
Describe a carotid artery bulb
- heavily calcified bulb or carotid artery aneurysm
- may be palpable
- often pulsatile
Describe the causes of a jugular vein thrombosis
Can occur as a consequence of indwelling pacemakers, central venous lines, trauma, surgery, infection, IVDU, compression by tumour, mediastinal lymphadenopathy
Describe the appearance of the a jugular vein thrombosis
Acute= pain, fever, tender, swelling
Chronic- painless, hard mass
Describe the ultrasound appearance of a jugular vein appearance
Acute- appears as ill-defined fascial planes with echogenic matter wihitn the vein, non-compressible, no flow with valsalva
Chronic- normal fascial planes, thrombus well-organised and echogenic
Why would you get a jugular vein thrombosis?
Inflammatory or infiltrative cervical lymphadenopathy
May be tumour thrombus associated with follicular or anaplastic carcinoma of thyroid
Describe the normal appearance of cervical lymph nodes
A normal lymph node is 2-5mm in diameter. Tonsillar lymph nodes are normally larger. Most normal nodes have a flattened, elongated, oval shape with a length:width ratio >2. They are usually hypoechoic with a fatty hilum
Describe the appearance of reactive or suspicious lymph nodes.
String of pearls appearance along the jugular vein of enlarged lymph nodes.
Malignant nodes tend to be round with a length:width ratio <1.5. They can be hypo-isoechoic with an obliterated fatty hilum. They can take on features of the primary with variable blood flow. They may have undergone necrosis and appear cystic.
What are the salivary glands?
parotid, submandibular and sublingual- they are responsible for a large portion of total saliva
