Learning objectives
Describing the varied appearances of subcutaneous epidermal inclusions cysts and its complications on ultrasonography.
Differentiating epidermal inclusion cysts from other commonly encountered subcutaneous lesions.
Background
Epidermal inclusion cysts are common benign lesions which occur due to the migration of epidermal tissue into the dermis or subcutaneous tissues.[1]
This abnormal localization can occur due to aberrant embryogenesis wherein the ectodermal cells are misplaced during cellular differentiation or traumatic transplantation of the epidermis into the dermis.[2] Other causes include inflammation of the pilosebaceous structures or infection of the eccrine duct with human papilloma virus 60.[1]
They can occur anywhere in the body with a predilection for face,
scalp,
neck and trunk.[2,3] Extremities...
Findings and procedure details
We will be discussing the varied ultrasonographic appearances of subcutaneous epidermal inclusion cyst and its complications and highlighting the imaging features of other common subcutaneous lesions which will help us differentiate them from epidermal inclusion cyst.
Ultrasonographic characteristics to be evaluated in cases of epidermal inclusion cyst are size,
shape,
margins,
echogenicity,
posterior acoustic enhancement,
internal echoes and vascularity.[3]
Ultrasound characteristics:
Size: It can vary from few millimeters to centimeters in size (the longest diameter),
however they have a mean size of 2-3cms.
[2] Fig....
Conclusion
Diagnosis of subcutaneous epidermal inclusion cyst poses a dilemma owing to the overlap of imaging features with other subcutaneous lesions,
however after having a basic understanding of the characteristic appearances of epidermal inclusion cysts,
its diagnosis can be made with high yield.
Personal information
Dr.
Kunal Arora
Third year resident,
Dr.
DY Patil Hospital,
Navi Mumbai
Maharashtra,
India
References
Houdek MT,
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Taljanovic MS.
Giant epidermal cyst of the gluteal region.Radiology Case Reports.
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Lee,
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Joo,
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Song et al.,
“Relationship between sonographic and pathologic findings in epidermal inclusion cysts,”Journal of Clinical Ultrasound,
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374–383,
2001
Kim HK,
Kim SM,
Lee SH,
et al.Subcutaneous epidermal inclusion cysts: Ultrasound (US) and MR imaging findings.Skeletal Radiol2011;40:1415–9
Yuan WH,
Hsu HC,
Lai YC,
Chou YH,
Li AF.
Differences in sonographic features of...