Primary Cutaneous CD4-Positive Small/Medium T-Cell Lymphoproliferative Disorder

**Semantic type:** Neoplastic Process

**Definition:** A primary cutaneous T-cell lymphoproliferative disorder composed of small to medium-sized CD4-positive, CD8-negative, and CD30-negative pleomorphic T-lymphocytes in the dermis. A small number of large pleomorphic T-lymphocytes, focal epidermotropism, and subcutaneous involvement may be seen. It usually presents with a solitary plaque or tumor on the face, neck, or upper trunk. The clinical behavior is almost always indolent, and most patients present with localized disease.

**Synonyms:** - PCSM-LPD - Primary Cutaneous CD4-Positive Small or Medium T-Cell Lymphoproliferative Disorder - Primary Cutaneous CD4-Positive Small/Medium T-Cell Lymphoma - Primary Cutaneous CD4-Positive Small/Medium-Sized Pleomorphic T-Cell Lymphoproliferative Disorder - Primary Cutaneous CD4-Positive Small/Medium-Sized T-Cell Lymphoproliferative Disorder - Primary cutaneous CD4-positive small/medium T-cell lymphoma