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SKIN LESIONS:
AN ULTRASONOGRAPHIC APPROACH
FOR A MULTIDISCIPLINARY
MANAGEMENT
M Drake-Perez, R Landeras-Alvaro,
E Gallardo-Agromayor, M Gonzalez-Vela,
E Trillo, E Lopez-Uzquiza
Hospital Universitario Marqués de Valdecilla
Santander, Spain.
NO DISCLOSURES
Objectives
• To review the sonoanatomy of the skin.
• To define the high-frequency ultrasound features of benign
and malignant skin lesions, correlating them with the
pathological findings.
• To emphasize the utility of ultrasounds in the diagnosis, the
medical or surgical treatment planning, and the recurrence
prevention of many skin conditions.
The utility of ultrasounds in dermatology has increased
considerably, mainly because of the better resolution of the new
ultrasound machines, and due to the use of higher frequency
transducers.
It is recommended to use a broadband transducer with a
center frequency of at least 15 MHz in order to study the skin
properly.
Sonoanatomy of the skin
Three layers:
*
- Epidermis: 0,06-0,6 mm. Most
superficial layer, hyperechoic due to
keratin content.
- Dermis: 1-4 mm. Connective tissue,
vessels, lymphatics, nerves, glands…
- Hypodermis: 5-20 mm. Mainly adipose
tissue.
(*): Fat lobule. (Arrows): Connective tissue septa.
Picture A shows normal
hyperechoic epidermal layer.
A
B
Picture B shows a thickened
epidermis, typically found in
palms and soles.
What to include in the report:
•
•
•
•
•
Localization (in the body and within the skin layers)
Margins (regular, irregular, signs of infiltration)
Size
Doppler: Vascularization pattern
Adjacent structures (muscles, bones…)
• Elastography (optional): Elastic properties.
Skin lesions
A) Focal benign lesions
B) Malignant tumors
C) Diffuse conditions
D) Exogenous components
Skin lesions
- Epidermal inclusion cyst
A) Focal benign lesions
B) Malignant tumors
C) Diffuse conditions
- Pilonidal cyst
- Skin adnexal derived: Trichilemmal cyst,
pilomatricoma, hidradenitis, dermal eccrine
cylindroma, eccrine hidradenoma…
- Pyoderma gangrenosum
- Dermatofibroma
- Glomus tumor
- Leiomyoma and angioleiomyoma
- Neurofibromas
- Vascular malformations
- Traumatic lesions: Fat necrosis, hematomas
- Others: Hyperkeratosis vs papilloma,
piezogenic pedal papules, chondrodermatitis
nodularis helicis, semicircular lipoatrophy,
pretibial myxedema
D) Exogenous components
A) Focal benign lesions
EPIDERMAL INCLUSION CYST
Ultrasound features depend on
time of evolution.
- Round, well defined margin ( )
- Posterior enhancement
- Lateral shadows
Pathology reveals squamous
stratified epithelium with an
inner granular layer, but no sebum.
Images: Long term epidermal inclusion cyst with patchy hypoechoic foci inside and
mostly green signal on elastography (soft).
A) Focal benign lesions
EPIDERMAL INCLUSION CYST
*
B
A
C
*
D
E
Images: Infected epidermal inclusion cyst, suspected by a high peripheric vascularization
(D). Other typical ultrasound features: Well defined round lesion, subepidermal tracts
(* A and C), inner soft signal, with a hard peripheric signal (B).
A) Focal benign lesions
TRICHILEMMAL CYST
Usually found in the scalp, associated with focal alopecia. They develop from the
external sheath of the pilose follicle, and do not present with a subepidermal tract.
They contain compact keratine, hair fragments, oleous material, and may calcify.
Ultrasound: Hypoechoic and well defined lesions, situated in dermis or
hypodermis, often with internal debris or calcium and posterior enhancement
(arrows).
A) Focal benign lesions
PILONIDAL CYST
A
C
B
D
Due to trapped pilose follicle or repetitive trauma. Usually found in the intergluteal
region. Ultrasound: Hypoechogenic and irregular tract extending through the dermis
and subcutaneous fat, with hyperintense lineal foci corresponding with pilose material
(arrows). If infected, it will present with peripheric vascularization (A and D).
A) Focal benign lesions
PILOMATRICOMA
*
A
B
*
C
Typical in children and young adults. Lesion derived from
the pilose follicle matrix.
Ultrasound: Hypoechoic lesion with hypoechoic
pseudocapsule (arrows) and internal hyperechoic foci
corresponding to calcification (*). Variable vascularization
(B: peripheric, D: peripheric and central). Hard-lesion
features on elastography (E).
D
E
A) Focal benign lesions
DERMAL ECCRINE CYLINDROMA: Rare tumor. Ultrasound: Homogenous lobulated and
vascularized lesion in the superficial dermis. Pathology: Proliferation of small and
homogenous basaloid cells, situated surrounding the vessels.
*
ECCRINE HIDRADENOMA: Derived from eccrine sweat glands. Ultrasound:
Subepidermal tract (arrow), hyperechoic internal foci (*) and intense vascularization.
A) Focal benign lesions
GLOMUS TUMOR
Painful lesion situated mainly in acral parts (subungueal).
Ultrasound: Well circumbscribed or encapsulated dermal
nodule. Posterior enhancement. Highly vascularized, with
arterial flow within the mass.
Pathology: Solid proliferation of round or poligonal
monomorphic cells, with eosinophilic cytoplasm and
hypercromatic nuclei, with a fibrous stroma.
A) Focal benign lesions
PRETIBIAL MYXEDEMA: A classical finding in Graves disease. Ultrasound: Dermal
thickening with tracts extending into subcutaneous tissue (arrows). Presence of
internal vessels. Pathology: Abundant myxoid material in dermis.
A) Focal benign lesions
DERMATOFIBROMA
Slow growing lesion. Ultrasound: Not well circumscribed, hypoechoic and
heterogenous. Usually hypovascular, might present with thin and slow-flow vessels.
They can associate distorsion or increase of the local pilose follicules. Pathology:
Fusiform cells and hyaline collagenous stroma.
A) Focal benign lesions
NEUROFIBROMA Benign lesion of the
peripheral nerve. Solitary or multiple (NF I).
Ultrasound: Hypoechoic, no encapsulated.
Pathology: Mixed proliferation of neurilemal
and fibroblastic cells with collagen.
A) Focal benign lesions
DERMATOFIBROMA
PIOLEIOMYOMA (Originated from smooth muscles cells in hair.)
ANGIOLEIOMYOMA originated from smooth muscles cells in dermal
veins.
Both tumors are usually painfull. Ultrasound: Not encapsulated,
infiltrating the dermis. Hypoechoic, well vascuarized.
Skin lesions
A) Focal benign lesions
B) Malignant tumors
C) Diffuse conditions
- Basal cell carcinoma
- Squamous cell carcinoma
- Malignant melanoma
- Merkel cell carcinoma
- Dermatofibrosarcoma protuberans
- Kaposi´s sarcoma
- Vascular tumors
- Cutaneous metastases
- Hematologic disease: Cutaneous lymphoma,
leukemia
D) Exogenous components
B) Malignant tumors
BASAL CELL CARCINOMA: Most frequent skin tumor, in sun-exposed
areas. Ultrasound: Hypoechoic and irregular lesion. Internal echoes
representing keratine nidus (arrows). Vascularized. Pathology: Epithelial
proliferation of basaloid cells with a desmoplastic stroma.
“Hard lesion” in elastography
Internal vascularization
B) Malignant tumors
SQUAMOUS CELL
CARCINOMA
Second malignant tumor. Tends to be more agressive than basocelular,
usually with node metastasis at presentation. Ultrasound: Irregular
lesion that may infiltrate adjacent tissues as bone or cartilage. Abundant
vascularization and “hard” pattern in elastography. Pathology:
Keratinocytes and atypical squamous epithelium.
B) Malignant tumors
CUTANEOUS T-LYMPHOMA
Ultrasound: Paniculitis-like, afecting the subcutaeous tissue, with
thicker and hypoechoic septa (*) and increased vascularization.
Pathology: Atypical lymphoid cells and dermal-hypopdermal
infiltration.
*
*
B) Malignant tumors
*
*
*
MERKEL CELL CARCINOMA: Sun-exposed áreas. Usually purple,
fast-growing and no painful lesions. Ultrasound: Echogenic thickening
of dermis (*) and irregular hypodermal infiltration.
Pathology: Hyperchromatic nuclei small cells that proliferate creating
a solid nidus formation. Cells are positive for CK20.
B) Malignant tumors
AXILLARY MELANOMA “INTRANSIT” METASTASES:
Multiple nodules, hypoechoic, irregular, vascularized
and with a “hard-pattern” in elastography, in a patient
with a known malignancy must be considered
suspicious. Pathology: Big pleomorphic cells with
abundant melanotic pigment in its cytoplsm.
B) Malignant tumors
DERMATOFIBROSARCOMA PROTUBERANS: Slow-growing and
intermediate malignant tumor. Ultrasound: Localized in hypodermis,
mild peripheral vascularization. Pathology: Adipose tissue infiltrated
by a proliferation of fusiform cells with a storiform pattern.
B) Malignant tumors
*
KAPOSI´S SARCOMA
*
Sistemic, multifocal condition, characterized by a proliferation of
endothelial cells, related to HHV 8. Ultrasound: Irregular and
hypervascular lesions in dermis (arrows) and hypodermis (*), that may
canker.
Skin lesions
A) Focal benign lesions
B) Malignant tumors
C) Diffuse conditions
- Psoriasis
- Scleroderma
D) Exogenous components
C) Diffuse conditions
SCLERODERMA
Condition characterized by a sclerosis of the skin of unknown
etiology. It can be presented in a localized form (morphea-next slide)
or diffuse (pictures below).
There is thickening of the dermis and of the subcutaneous
tissue, with formation of hyperechoic and thick bands of connective
tissue in advanced phases.
CREST Syndrome:
Subcutaneous calcifications.
Picture on the right shows a
painful subcutaneous
calcification, fistulating to the
skin (arrows)
C) Diffuse conditions
MORPHEA (localized form of SCLERODERMA)
*
Ultrasound:
Hyperechoic fat lobules
(arrows), septa
hiperemia (*) and
dermal thickening.
Pathology: Perivascular
inflammatory cells that
extends to subcutaneous
fat. Expansion of the
dermis with thickened
collagen bundles and
replacement of lobes by
collagen.
C) Diffuse conditions
MORPHEA (localized form of SCLERODERMA)
Deep morphea: Patient presenting with two palpable lesions situated in
the gluteal region and in the knee, showing patchy and linear purple
areas. Ultrasounds show thickening and hypoechoic septa, with
hyperechoic fat lobules.
Skin lesions
A) Focal benign lesions
B) Malignant tumors
C) Diffuse conditions
D) Exogenous components
6.- Exogenous components
They usually present as a hyperechoic images surrounded by a
hypoechoic halo corresponding to the inflammatory reaction. Imaging is
required for assessing complications such as abscesses or fistulae, or
guiding for its subtraction.
A
C
B
PREVIOUS FREE SILICONE
INJECTIONS Ultrasound:
Superficial subcutaneous
hyperechogenicity with deeper
echo attenuation (A and C),
edematous areas (B) and small
zones of fat necrosis (arrows).
6.- Exogenous components
Left
Right
HYALURONIC ACID The patient presented with bilateral infraorbital
nodules. Ultrasound: Hypoechoic nodules without vascularization in
between the fat lobules. Pathology: Fibroadipous tissue and nodular
areas of an acellular material, surrounded by foreign-body giant cells.
Conclusions
• Ultrasound is a very useful tool in the assess of many
skin conditions, modifying the medical or surgical
treatment, helping in the follow-up, or improving the
cosmetic outcome.
• Radiologists should be aware of the normal
sonoanatomy of the skin, and know how to recognize
the common and uncommon echographic features of
different skin lesions.