Pathology of Superficial Structures

A superficial epidermal cyst may also be referred to as an

epidermal inclusion cyst, an epidermoid cyst, or possibly a sebaceous cyst

True sebaceous cysts are

uncommon

Superficial epidermal cysts are most likely found in the

scalp, face, neck, trunk, or back

Superficial epidermal cysts are potentially the result of an

obstructed hair follicle

sonographic appearance of skin layers and muscle in the thigh. Longitudinal image of the epidermis and dermis (white arrowheads), the subcutaneous fat (S), the rectus femoral muscle (RF), connective tissue (open arrowheads), the vactus intermedius muscle (VI), and the femur (F).

clinical findings of a superficial epidermal cyst

1. Visible, palpable mass just under the skin

2. Pain and redness in the area

sonographic findings of a superficial epidermal cyst

1. Anechoic, hypoechoic, complex, or hyperechoic cyst or mass

2. Pseudotestis appearance

A ganglion cyst is a common mass found along the dorsal aspect of the

hand and wrist

Large ganglion cysts in the wrist have been referred to as —, because individuals in the past have used large books—like the Bible—to reduce the cyst by slamming the large book against it.

Bible bumps

clinical findings of a ganglion cyst

1. Palpable mass most often located along the dorsal aspect of the hand or wrist

2. Can be painful

Ganglion cyst. This small cyst was located in a patient’s wrist and was determined to be a ganglion cyst.

sonographic findings of a ganglion cyst

1. Noncompressible, anechoic mass with acoustic enhancement

2. May contain debris or septations

Lipomas are usually — and may be observed during a physical examination

compressible

clinical findings of a superficial lipoma

1. asymptomatic

2. Obvious mass under the skin

3. compressable

sonographic findings of a superficial lipoma

1. Most likely an isoechoic mass as compared to the surrounding tissues

2. Typically have an oval shape

Lipoma. This lipoma (between arrows) appearing as an oval hyperechoic mass is noted just under the skin.

clinical findings of a superficial hemangioma

1. asymptomatic

2. Red or reddish-purple, raised mass on the skin

sonographic findings of a superficial hemangioma

1. Blood flow may be detectable with color Doppler

2. Hypoechoic

A Baker cyst, or —

popliteal cyst

A Baker cyst, or popliteal cyst, is located in the popliteal fossa,

behind the knee

These cysts are common and a result from the accumulation of 508 synovial fluid from a weakening in the joint capsule of the knee, as seen in conditions such as —

rheumatoid arthritis or osteoarthritis.

Baker cysts. A. An uncomplicated Baker cyst (between calipers and arrows) appears as an anechoic mass in the popliteal fossa. B. A large Baker cyst (arrows) in a patient with rheumatoid arthritis contains some echogenic debris and pannus

A Baker cyst may be seen in the presence of rheumatoid arthritis or other

knee joint issues.

clinical findings of a baker cyst

1. asymptomatic

2. focal tenderness in the popliteal fossa

sonographic findings of a baker cyst

1. Anechoic mass with posterior enhancement

2. Complicated Baker cysts may contain echogenic fluid, debris, or septations

A pilonidal cyst is most often found within the

natal cleft

a pilonidal cyst is also referred to as — and may also be seen within the fingers or toes

pilonidal sinus

Pilonidal means

“nest of hair.”

pilonidal cysts are comprised of

loose hairs and skin debris

Patients who are more prone to pilonidal cyst include those who

sit for an extended amount of time and hairdressers

During World War II, the pilonidal cysts were linked with soldiers who had to endure long, bumpy jeep rides, and thus they were termed

“jeep disease.”

clinical findings of a pilonidal cyst

1. Edema, warmth, and pain in the area of the cyst

2. Bloody drainage from the cyst may be present

sonographic findings of a pilonidal cyst

1. Complex, subcutaneous mass

2. Hyperemia around the mass

3. Hypoechoic tract may be seen extending from the cyst to the skin surface

Typical location of a pilonidal cyst.

Pilonidal cyst. This pilonidal cyst appeared as a complex mass (M) at the tip of the distal spine (arrow) in this infant.

— is infection and subsequent inflammation of the skin and subcutaneous tissue

Cellulitis

cellulitis is most often caused by

Staphylococcus aureus and Streptococcus pyogenes

A hidden abscess is termed an

occult abscess

abscesses are focal fluid collections that are often complex and have a — that can be detected with color Doppler

peripheral rim of hyperemi

When cellulitis is identified, the sonographer should look carefully for a — that may represent abscess development

complex focal fluid collection

clinical findings of cellulitis

1. Red, tender, warm area of the skin

2. Possible elevated white blood cell count (especially with abscess development)

sonographic findings of cellulitis

1. Hypoechoic, edematous strands within the soft tissue (cobblestone appearance)

sonographic findings of a superficial abscess

1. Hypoechoic, edematous strands within the soft tissue (cobblestone appearance)

2. Focal fluid collection that is often complex, denoting the abscess

3. A peripheral rim of hyperemia may be detectable with color Doppler

Malignant melanoma accounts for up to — of skin cancers.

11%

Melanoma is also the most likely — to metastasize to the subcutaneous fat

primary tumor

sonographic findings of metastatic melanoma

1. solid, hypoechoic mass