Skin Epithelioid Fibrous Histiocytoma

**Semantic type:** Neoplastic Process

**Definition:** A benign primary cutaneous neoplasm of unknown histogenesis that presents as an exophytic nodule and is characterized by the presence of epithelioid neoplastic cells. It is probably biologically distinct from conventional fibrous histiocytoma of the skin and its subtypes. ALK gene rearrangement is present in most cases.

**Synonyms:** - Cutaneous Epithelioid Fibrous Histiocytoma - Cutaneous Fibrous Histiocytoma, Epithelioid Variant - Dermatofibroma, Epithelioid Variant - EFH - Epithelioid Cell Histiocytoma - Epithelioid Dermatofibroma - Epithelioid Fibrous Histiocytoma - Skin Fibrous Histiocytoma, Epithelioid Variant