Learning objectives
-To review the normal ultrasound appearance of the skin layers.
-To enumerate the most common benign and malignant soft tissue masses that we can find in our daily practice,
and describe the common findings for each of them.
Background
Soft tissue masses are a very common presenting complaint.
Most of the times these masses require imaging for diagnosis,
and ultrasound is the first modality in most of the cases.
In each of the skin layers there are different cells and structures,
each of them can originate different tumors.
-Epidermis is the most superficial layer,
hyperechoic and up to 0.6 mm.
-Dermis (1-4 mm) is less hyperechoic,
with hypoechoic areas (vessels,
sebaceous glandules,
hair follicles and nerves)
-Subcutaneous fat layer
Imaging findings OR Procedure Details
Ultrasound findings can help us diagnose soft tissue lesions mainly by their appearance (cystic,
solid…),
histologic origin (epidermic,
dermic,
hypodermic),
anatomic localization and vascularization.
Epidermic inclusion cysts:
Hypoechoic cysts )posterior acoustic enhancement) connected to dermis,
they can show a subepidermic track
Can be heterogeneous (if infected or chronic) or with lobulated/irregular margins with surrounding foreign body reaction (because of keratin leak if it breaks)
Trichilemal cyst:
Heterogeneous cysts (posterior acoustic enhancement) with hyperechoic lines and calcification.
They appear in the head.
It may not connect...
Conclusion
Ultrasound is a powerful tool for diagnosis or help diagnosis orientation of soft tissue masses.
Adequate knowledge of skin histology and soft tissue masses can help us suggest a diagnosis or adequate differential diagnosis,
and realize the need for other imaging techniques or biopsy.
References
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Dermatologic Ultrasound with Clinical and Histologic Correlations.
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Muskuloskeletal Fibromatoses: Radiologic-Pathologic Correlation.
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Granular cell tumour of the pectoral muscle mimicking breast cancer.
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Knuckle pads – a rare finding.
Journal of Ultrasonography 2012; 12: 493–498
ÒWhittle C et al.
Finger Chondroid Syringoma as a Hypoechoic Subcutaneous Nodule in Ultrasound.
Ultrasound Quarterly 2013;29:211Y213
ÒBhosale PR,
Patnana M,Viswanathan C,
Szklaruk J.
The inguinal canal: anatomy and...