epidermal inclusion cyst

Nuchales
Atherom in der MRT: Oben T2 und DWi axial, unten FLAIR und T1 KM sagittal.
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Atherom der
Kopfhaut links hochparietal: In der Computertomografie reicht der Befund bis unmittelbar an die Hautoberfläche heran. Randständig betonte Verkalkungen. Knochenfenster links, im Weichteilfenster rechts oben, Hirnfenster rechts unten.
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Atherom der
Kopfhaut, oben im Weichteilfenster unten im Knochenfenster.
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Intrakranielle
Epidermoidzyste der Pinealisregion rechts paramedian. Magentresonanztomographie DWI axial: Der Befund zeigt sich deutlich hyperintens.
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Epidermal
inclusion cyst of the tongue - a rare entity. Axial T1 with contrast shows a well-defined lesion (1.5x1.0x1.2 cm) with mild peripheral enhancement and low signal intensity.
www.eurorad.org • CC by-nc-sa-4.0
Pseudotumoural
soft tissue lesions of the foot and ankle: a pictorial review. Ultrasound of epidermoid cyst on the sole of the foot. The ultrasound images demonstrate a hypoechogenic polylobular lesion with posterior acoustic enhancement containing some scattered echogenic reflective material. The cyst is located in the subcutaneous fat superficial to the flexor tendon of the second digit
insightsimaging.springeropen.com • CC-by-2.0
Extratesticular
epidermal inclusion cyst of the scrotum (ECR 2016 Case of the Day). Transverse T1-weighted image depicts homogeneous right extratesticular mass (arrow), isointense to the ispilateral testis (arrowhead).
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Extratesticular
epidermal inclusion cyst of the scrotum (ECR 2016 Case of the Day). Coronal T2-weighted image shows right extratesticular mass (arrow), close to the ipsilateral spermatic cord (long arrow), mainly hyperintense, with signal similar to that of normal testes (arrowheads), surrounded by a low signal intensity capsule.
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A rare case
of extratesticular scrotal epidermoid cyst. A non-vascular lesion measuring 15x12 mm was noted indenting the lateral aspect of the right epididymal head with a whorled appearance and central calcific focus giving it a "target" or "bulls eye" appearance.
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Epidermal
cyst of the ischiorectal fossa. No rim enhancement is appreciable on axial post-contrast image.
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Toddler with
stridorLateral radiograph of the airway shows a mass at the base of the tongue.The diagnosis was epidermal inclusion cyst of tongue.
pediatricimaging.org • CC-by-nc-sa 4.0
Intrakranielle
Epidermoidzyste der Pinealisregion rechts paramedian. Magentresonanztomographie T1w axial nach Kontrastmittel: Keine KM-Aufnahme
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Intrakranielle
Epidermoidzyste der Pinealisregion rechts paramedian. Magentresonanztomographie T2w sagittal: Der Befund zeigt sich nahezu liquorisointens. Aber siehe FLAIR und DWI.
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Atherom der
Kopfhaut rechts hochparietal Knochenfenster und Hirnfenster
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Intrakranielle
Epidermoidzyste der Pinealisregion rechts paramedian. Magentresonanztomographie T2w axial: Der Befund zeigt sich nahezu liquorisointens. Aber siehe FLAIR und DWI.
Wikipedia • CC BY-SA 3.0
Intrakranielle
Epidermoidzyste der Pinealisregion rechts paramedian. Magentresonanztomographie T1w coronar nach Kontrastmittel: Keine KM-Aufnahme
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Epidermal
cyst of the ischiorectal fossa. A well-circumscribed large cyst occupies the right ischiorectal fossa; the rectum and the vagina are contralaterally displaced.
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Epidermal
cyst of the ischiorectal fossa. Axial image: the cyst is unilocular and delineate by thin hypointense rim.
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Sebaceous
cyst in the left malar area (right image)
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Proliferating
trichilemmal cyst • Proliferating trichilemmal cysts - Ganzer Fall bei Radiopaedia
Anan R, Proliferating trichilemmal cysts. Case study, Radiopaedia.org (Accessed on 26 Dec 2023) https://doi.org/10.53347/rID-97480 • CC by-nc-sa 3.0 (modified)
Pseudotumoural
soft tissue lesions of the foot and ankle: a pictorial review. Epidermoid cyst (different patient from that in Fig. 7). Axial fat-suppressed T2-WI (a), coronal T1-WI (b) and coronal contrast-enhanced T1-WI (c). Unilocular, well-defined subcutaneous lesion (arrows) at the medial aspect of the ankle. The lesion has intermediate SI on T2-WI with some small areas of lower SI (probably due to keratinous debris), and is slightly hyperintense to muscle on T1-WI. A peripheral rim enhancement is seen (arrowhead), without internal enhancement
insightsimaging.springeropen.com • CC-by-2.0
Epidermal
inclusion cyst • Epidermal inclusion cyst of the external auditory canal - Ganzer Fall bei Radiopaedia
Ranchod A, Epidermal inclusion cyst of the external auditory canal. Case study, Radiopaedia.org (Accessed on 14 Mar 2023) https://doi.org/10.53347/rID-93335 • CC by-nc-sa 3.0 (modified)
Proliferating
trichilemmal cyst • Proliferating trichilemmal cysts - Ganzer Fall bei Radiopaedia
Kabakus I, Proliferating trichilemmal cysts. Case study, Radiopaedia.org (Accessed on 26 Dec 2023) https://doi.org/10.53347/rID-56421 • CC by-nc-sa 3.0 (modified)
Pseudotumoural
soft tissue lesions of the hand and wrist: a pictorial review. Subcutaneous epidermoid cyst with involvement of the adjacent bone of the terminal phalanx of the right fifth finger. a Plain radiograph showing a well-defined osteolytic defect at the radial side of the distal phalanx. Note cortical destruction of the radial cortex. b Coronal SE T1-WI. The lesion is of intermediate signal intensity (arrows) with some internal areas of relatively high signal. c Coronal TSE T2-WI. High signal intensity of the lesion (arrows). d Coronal FS SE T1-WI after intravenous injection of gadolinium contrast medium. There is only subtle peripheral enhancement (arrows) of the lesion
insightsimaging.springeropen.com • CC-by-2.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Epidermal inclusion cysts or epidermal cysts are common cutaneous lesions that represent proliferation of squamous epithelium within a confined space in the dermis or subdermis.

Terminology

These are occasionally termed sebaceous cysts, although this is a misnomer as the lesion does not originate in the sebaceous glands. As such, the term epidermal inclusion cyst is preferred.

These are also called epidermoid cysts, which in turn are sometimes considered a type of dermoid cyst .

Clinical presentation

Epidermal cysts are either found incidentally or present as a firm non-tender lump. If they rupture a local inflammatory response to the necrotic debris released can mimic infection. Although they can be found anywhere, they are typically located on the scalp, face, neck, trunk, and back . Rarely they can be seen within bones representing an intraosseous epidermoid cyst .

Rarely epidermal cysts can undergo malignant degeneration with squamous cell carcinoma .

Pathology

They are thought to occur as a result of :

  • traumatic/surgical implantation
  • occlusion of the pilosebaceous unit
  • congenital rests of cells
  • human papillomavirus type 57 or 60 infections implicated palmoplantar epidermoid cysts

They are closely related to cholesteatomas, and should not be confused with epidermoid cysts of the CNS.

Radiographic features

On all modalities, they appear as well-circumscribed masses arising in or just deep to the skin.

Ultrasound

Well-circumscribed predominantly hypoechoic mass. Typical shapes include :

  • ovoid to spherical: ~70%
  • lobulated: ~20%
  • tubular: ~8%.

If small, it can mimic a typical anechoic cyst. Using subcutaneous fat as a reference, lesions tend to be hypoechoic. Larger lesions can be a little heterogeneous due to the presence of mucoid, fat, calcification or pus. Usually no associated vascularity. They, however, can have a variable appearance if ruptured, occasionally associated with vascularity and lobulated contours. On color Doppler, it may show twinkling artefact .

CT

The density of epidermal inclusion cysts is similar to that of water. The margins are usually slender and sclerotic.

MRI

Imaging on MRI is similar to that of CNS epidermoid cysts or cholesteatomas, namely the content of the cyst is similar to CSF/water. In unruptured cases, typical signal characteristics include:

  • T1: low/intermediate signal
  • T2: high signal
  • DWI
    • some true restricted diffusion (similar to soft tissue on ADC)
    • superimposed T2 shine through
  • T1 C+ (Gd)
    • no enhancement centrally
    • may have thin peripheral enhancement

With ruptured cases, they may have septa, show thick and irregular rim enhancement, and can be accompanied by a fuzzy enhancement in surrounding subcutaneous tissues.

Treatment and prognosis

They are benign and generally do not require treatment. If infected they may require incision and drainage. If they continue to grow they may require excision.

Complications
  • superimposed infection
  • rupture
  • concurrent occurrence of tumors within them, e.g. melanoma (very rare) 

Differential diagnosis

General imaging differential considerations include:

See also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu epidermale Inklusionszyste:
Epidermoidzyste
 
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intrakranielle
Epidermoidzyste
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Epidermoid in
der Kalotte
insightsimaging.springeropen.com • CC-by-4.0
intraventricular
epidermoid
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Dermatofibrosarcoma
protuberans
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Epidermoidzyste
Finger
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testicular
epidermoid cyst
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Malherbe-Tumor
 
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