Lumps and Bumps

9 - 13MHz

What is the recommended frequency range for a transducer when imaging superficial structures?

3.5-7MHz

What is the recommended frequency range for a transducer when imaging deep lesions?

1. Graded compression to see whether mass is compressible.

2. Dynamic scanning such as: standing patient up or rolling patient to the side, extending or flexing the joint.

3. Palpate the lump.

4. Alter machine setting such as gain, focal zone, THI.

What are the scanning techniques used in ultrasound imaging? (Name 4)

Lipoma, haemangioma, haematoma, and bursitis

Which types of masses are generally compressible during ultrasound imaging? (Name 4)

1. Whether it is a pseudomass

2. Size

3. Shape

4. Echogenicity

5. Internal content: cystic, solid

6. Vascularity

7. Location relative to surrounding structure

What are the characteristics used to characterize a lump?

Have lower resistive index

What is a characteristic of vascular flow in an inflammatory mass compared to a malignant mass?

1. Subcutaneous fatty accumulation.

2. Muscle asymmetry.

3. Accessory muscle.

4. Bony irregularities.

Describe the sonographic features of lesions which commonly present as superficial masses, Pseudomass (4)?

A benign fatty tumor

What is a lipoma?

Most occur in subcutaneous fat

Where do most lipomas occur?

Palpable, compressible, mobile, painless

What are the clinical presentations of a lipoma?

Elliptical shape, non-vascular, echogenicity varies, well-defined borders, linear reflective striations

Describe the appearance of a lipoma

Lipomas are generally encapsulated, but not always

Are lipomas always encapsulated?

Most commonly hyperechoic to surrounding subcutaneous fat

What is the most common echogenicity of lipomas?

The fibrous component within, making it appear hypoechoic

What gives a lipoma a pure fat appearance?

When the lipoma is hyperechoic and tender

When should you consider angiolipoma or fat necrosis?

Within muscle or between muscles

Where do deep-seated lipomas arise from?

Ovoid, striated, non-compressible, no doppler signal, can be isoechoic to muscle

What is the typical appearance of a deep-seated lipoma?

Muscle fibers are separated by a proliferation of fat and replaced by fat in a bland fashion.

What happens to muscle in infiltrative lipoma?

It appears as a heterogenous striated mass.

How does infiltrative lipoma appear?

Extensive infiltration of the subcutaneous and muscular tissue by fatty tissue.

Lipomatosis: What is it?

A malignant fat-containing tumor.

What is liposarcoma?

At one spectrum is the low grade well-differentiated liposarcoma, then there is the myxoid subtype, the other spectrum is the high grade poorly differentiated pleomorphic liposarcoma.

What are the three spectra of liposarcoma?

Grades of malignancy.

What does the image appearance of liposarcoma depend on?

Thick septa, lobular pattern, internal vascularity, and heterogeneity.

What are the common appearances shared by all types of liposarcoma?

Fat.

What does well-differentiated liposarcoma mainly contain?

Well-defined, hypoechoic, thick septations, and nodules.

What are the typical appearances of well-differentiated liposarcoma?

Myxoid, round cell, fat component

What components are present in the myxoid subtype of tumors?

More myxoid content results in a more hypoechoic appearance

How does an increase in myxoid content affect the appearance of tumors?

They have anechoic areas due to necrosis

What distinguishes high grade or poorly differentiated tumors in terms of appearance?

A pocket of pus

What is an abscess?

Can range from an anechoic fluid collection to a complex mass

What are the two variable appearance spectra of an abscess?

Cystic, hypoechoic, irregular, posterior enhancement, mobile echogenic debris, hyperemia: peripheral rim-like pattern

What are the six possible appearances of an abscess?

Present after birth and regresses after reaching maximum volume

What is the occurrence and involution of haemangioma?

Endothelium

What is a haemangioma lined by?

Capillary, cavernous, and venous types depending on the nature of the predominant vessels within the lesion

What are the three types of haemangioma?

High vessel density and high peak arterial Doppler shift

What are the Doppler characteristics of haemangioma?

Can be hypoechoic or hyperechoic, homogenous or complex

What are the appearance characteristics of haemangioma?

Children most often have capillary haemangioma, while adults usually have cavernous type haemangioma

What types of haemangioma are common in children and adults?

Multiple cystic and with recognizable tubular channels

What are the characteristic appearances of subcutaneous haemangioma?

Ill-defined margins, mixed echogenicity, contain phleboliths, demonstrate no or little flow but colour filling may be elicited by transducer compression/standing patient erect or exercising the limb

What are the characteristics of intramuscular haemangioma?

Contusion trauma

What can cause fat necrosis?

Vascular impairment or fat saponification by lipase from blood

What are the causes of fat necrosis?

Oedema, haemorrhage, and fibrosis

What accompanies fat necrosis?

Hyperechoic area containing small hypoechoic spaces related to infarcted fat, can be ill-defined or focal, hypoechoic halo due to fibrous capsule

How does fat necrosis appear on imaging?

Cellulitis is typically more widespread and erythematous

How does fat necrosis differ from cellulitis?

Pain may be elicited over the tumour with pain radiating along the nerve distribution.

Peripheral nerve sheath tumour (for more detailed, look at previous module):

• A diagnostic symptom?

Perineural fibrosis, local vascular proliferation, edema of the endoneurium, axonal degeneration

What does Morton's neuroma consist of?

In the second or third intermetatarsal region at the level of the metatarsal heads

Where is the localized pain in Morton's neuroma typically felt?

Fusiform, hypoechoic, continuous with the plantar digit nerve

How does Morton's neuroma appear on imaging?

Neuroma

What occurs after a nerve is partially or completely disrupted by an injury?

A disorganized growth of nerve cells at the site of a nerve injury

What is a neuroma?

Pain or tingling sensation when pressure is applied

What are two symptoms of a neuroma?

Fibromatoses (superficial and deep fibromatoses), benign fibrous proliferation (nodular fasciitis, elastofibroma), fibrosarcomas and fibrous proliferation of infancy and childhood.

Fibrous tumors: Can be categorized into (4)?

Fibrous or connective tissue

What is a fibroma mostly made up of?

Tendon sheaths of the fingers or thumbs

Where do fibromas predominantly arise from?

Idiopathic, local irritation, injury

What can cause fibromas?

Well-defined, hypoechoic lesion

How do fibromas appear on ultrasound?

Giant cell tumor

What condition can fibromas not be differentiated from?

Dupuytren disease

What is another name for palmar fibromatosis?

Hypoechoic, homogenous, fusiform nodule single or multiple along the plantar fascia, can also appear as thickening.

Describe the appearance of plantar fibromatosis.

Proliferation of fibrous tissue within the plantar fascia

What causes plantar fibromatosis?

Avascular

Is plantar fibromatosis vascular or avascular?

Local pressure reproduces the pain

What symptom is associated with plantar fibromatosis?

Benign proliferation of fibroblasts and myofibroblasts.

What is nodular fasciitis?

Propensity to involve the volar aspect of the forearm and rapid growth which can be mistaken as soft tissue sarcoma.

What are the notable features of nodular fasciitis?

Tender lump.

What is a common symptom of nodular fasciitis?

Usually in the subcutaneous tissue.

Where is the usual location of nodular fasciitis?

It can also be found intra or inter-muscularly.

Where else can nodular fasciitis be located?

Well-defined, isoechoic or heterogeneous with isoechoic and hypoechoic areas, can have lobulation and vascularity.

What is the typical ultrasound appearance of nodular fasciitis?

It is a benign fibroelastic pseudotumor.

What is Elastofibroma dorsi?

It results from friction between the scapula and chest wall.

What causes Elastofibroma dorsi?

It is located at the inferior margin of the scapula, deep to the serratus anterior, rhomboid major, and latissimus dorsi muscle.

Where is Elastofibroma dorsi exclusively located?

It contains alternating fatty and fibrous tissue layers, producing a characteristic striated appearance with numerous hypoechoic fat lines and hyperechoic fibrous tissue interfaces.

What are the components of Elastofibroma dorsi and its resultant appearance?

Place the ipsilateral hand on the opposite shoulder to throw the scapula off the mass.

How can the scapula be moved off the mass for scanning Elastofibroma dorsi?

Malignant

• Ultrasound appearance (4)? Nonspecific, internal vascularity, heterogenous, can have calcifications.

Fibrosarcoma:

• It is a _ tumour.

Synovial hypertrophy

What is synovial cyst often associated with?

There is a joint-bursa communication with a one-way-valve-like mechanism

What is the mechanism involved in synovial cyst formation?

Synovial cysts have a synovial lining, while ganglion cysts are lined by dense fibrous connective tissue

How is a synovial cyst different from a ganglion?

Synovial cysts are more easily compressible due to their viscous content and less dense fibrous capsule compared to ganglion cysts

Why are synovial cysts more easily compressible than ganglion cysts?

Synovial cysts may appear solid or may be hypervascular, especially in patients with inflammatory arthropathy

What are the other possible appearances of synovial cysts?

Knee and hip

Where are synovial cysts commonly found?

Wrist, hand, ankle, and foot

Where are ganglion cysts commonly found?

Hypoechoic or anechoic, uni or multilobular, can have septations, thin and well-defined border, both can communicate with joint

What are some similar appearances between ganglion cysts and synovial cysts?

Mucoid degeneration of fibrous structures such as ligament, tendon, synovial joint.

What do ganglion cysts represent?

Stretching of the joint capsule or ligament stimulates mucin production, which eventually becomes encapsulated to form a ganglion cyst.

How are ganglion cysts formed?

Knee pain, swelling, palpable lump at the joint line

What are the symptoms of a meniscal cyst?

Formed when perimeniscal synovial fluid extravasates through a meniscal tear

How is a meniscal cyst formed?

Parameniscal or intrameniscal cyst

What are the alternative names for a meniscal cyst based on its location?

Cystic appearance, anechoic or hypoechoic, can migrate along tissue planes and be remote to the meniscus

What is the typical appearance of a meniscal cyst?

In the epidermis

Where are cutaneous cysts located?

Consist of dermal products such as keratin, cholesterol, protein, and cell membrane lipid

What are the compositions of cutaneous cysts?

Swollen sebaceous glands or hair follicles

From where do sebaceous cysts arise?

Round or oval, hypoechoic, internal debris, through transmission, well circumscribed, avascular, acoustic enhancement

How do cutaneous cysts typically appear?

Hypoechoic, lobular, ill-defined border, hyperaemia

How do ruptured cutaneous cysts appear?

A keratin-filled orifice that allows the cyst to communicate with the skin surface

What is a punctum in relation to cutaneous cysts?

Foreign bodies can migrate.

Why is scanning a large area needed when dealing with a foreign body?

Granuloma formation, infection, purulent tenosynovitis, septic arthritis, abscess, fistula, damage to adjacent nerve.

What are at least three potential consequences of a missed foreign body?

Wood: posterior shadowing. Glass and metal: reverberation artefact.

What appearance is associated with wood, glass, and metal foreign bodies on ultrasound?

Wood.

What is the most common material for foreign bodies?

Inflammatory reaction, pus, haematoma, or granulation tissue.

What does the echolucent area around a foreign body demonstrate?