Epidermal Cyst: Ultrasonography, Color Doppler Ultrasonography, and Strain Elastography Features. A Pictorial Essay.

I Purpose or Learning Objective: i To describe ultrasonography (US), color Doppler, and strain elastography (SE) features of epidermal cysts (ECs) and the differential diagnosis between ECs and malignant soft tissue tumors based on patterns reported in a literature review and from our experience. SE identifies four color patterns, from red (softer, pattern 1) to blue (harder, pattern 4), based on the stiffness of the lesion and of the pericystic tissue. I Methods or Background: i Epidermal inclusion cysts, also called epidermoid cysts, infundibular cysts, or sebaceous cysts, are benign cutaneous or subcutaneous cysts lined with stratified squamous epithelium and filled with keratin debris. [Extracted from the article]