Cutaneous lymphomas are a distinct subset of non-Hodgkin’s lymphoma. They are cancers of lymphocytes (white blood cells) that primarily involve the skin.
Classification is based on lymphocyte type: B-lymphocytes (B-cell) or T-lymphocytes (T-cell).
Cutaneous T-cell lymphoma (CTCL)
Cutaneous T-cell lymphoma (CTCL) is the most common type of cutaneous lymphoma that typically presents with red, scaly patches or thickened plaques of skin that often mimic eczema or chronic dermatitis. Progression from limited skin involvement is variable and may be accompanied by tumor formation, ulceration, and exfoliation, complicated by itching and infections. Advanced stages are defined by involvement of lymph nodes, peripheral blood, and internal organs. Most CTCLs typically fall into the category of indolent (i.e. chronic) lymphomas – treatable, but not curable and usually not life-threatening.
Cutaneous B-cell lymphomas (CBCL)
Cutaneous B-cell lymphomas (CBCL) are a less common version of cutaneous lymphomas, making up about 20-25% of all cutaneous lymphomas. CBCLs are B-cell non-Hodgkin’s lymphomas which originate in skin-based B-cells. Systemic or nodal B-cell lymphomas can secondarily involve the skin and when a skin biopsy shows B-cell lymphoma it is very important to make sure that the skin is the only organ involved and that this is not a systemic lymphoma presenting in the skin. The most common forms of CBCL are slow growing or indolent variations and respond well to mild treatments.