Dermal atypical lipomatous tumor/well-differentiated liposarcoma obfuscated by epidermal inclusion cyst: a wolf in sheep's clothing?

Epidermal inclusion cysts are an exceedingly common entity seldom seen in association with a malignant tumor. Herein, we report a unique case of an epithelial inclusion cyst seen in association with an atypical lipomatous tumor/well-differentiated liposarcoma. The epidermal inclusion cyst was delimited to the dermis and circumferentially enveloped by an atypical adipocyte tumor containing myxoid foci and comprised of lipoblasts. This case underscores the importance of scrutinizing the entirety of cysts and other ostensibly trivial dermal entities to avoid the pitfall of misdiagnosing a potentially serious tumor.