T-cell cutaneous lymphoma is the most common type of cutaneous lymphoma. CTCLs are often red and dry like eczema and can affect large parts of the body.
CTCLs make up the 75 to 80% of all primary cutaneous lymphomas (with the most common type being mycosis fungoides [MF]) and CBCLs the 20 to 25%. However, the distribution is different in other parts of the world.
For example, in Southeast Asia, CTCLs (excluding MF) are much more common than in the West and CBCLs are much rarer.
T-cell cutaneous lymphomas (CTCLs)
The two most common types of CTCL are:
- Mycosis fungoides (MF)
- Sézary Syndrome (SS)
Other forms of CTCL include:
- Primary cutaneous CD30+ lymphoproliferative disorders
- Subcutaneous panniculitis-like T-cell lymphoma
- Extranodal natural killer/T-cell lymphoma, nasal type
- Primary cutaneous peripheral T-cell lymphoma, unspecified
Most CTCLs are chronic lymphomas, with a very good prognosis and are treatable, and usually not life-threatening. MF is the most common form of CTCL. It follows a slow, chronic course, often of many years or decades, and very often does not extend beyond the skin. Most people suffer from the classic form of MF, but there are several rarer forms. Most patients who receive treatment live a normal life and in many the disease remains in remission for long periods of time.
The classic MF usually starts in the form of patches or plaques on the skin, and may be accompanied by itching. They can occur anywhere on the body, but are usually found on the torso or buttocks. In rarer cases, larger nodules or tumors may appear. In some cases it may present as erythroderma, while in a few patients it may present as an unpredictable course.
Rare forms of MF:
Follicular MF specifically affects the hair follicles, and can cause hair loss.
Sézary Syndrome (SS) is a rarer but more aggressive form of CTCL associated with MF, but it presents with more intense itching, redness all over the body (erythroderma), severe peeling of the skin and frequent hair loss. They may also show signs of fatigue, and have fever and swollen lymph nodes. SS is the only type of CTCL that affects the skin and blood.
Primary cutaneous CD30-positive lymphoproliferative disorders (PCCD30 + LPD): Two main types of such disorders are identified, accounting for about one-third of all CTCL diagnoses:
- Primary cutaneous CD30+ lymphoproliferative disorder: lymphomatoid papulosis (LyP)
- Primary cutaneous CD30+ lymphoproliferative disorder: anaplastic large cell lymphoma (PCALCL)
In both species, the CD30 protein is found on the surface of abnormal lymphocytes and the prognosis is excellent, with 10-year survival in 100% of patients with LyP and 90% of patients with PCALCL.
Lymphomatoid papulosis (LyP) is manifested by small macules and papules that may go away on their own, but tend to recur.
Primary cutaneous CD30+ lymphoproliferative disorder: anaplastic large cell lymphoma (PCALCL) is a slow-growing lymphoma, with characteristic skin lesions and nodules that can occur anywhere on the body and develop very slowly.
Rare types of cutaneous T-cell lymphoma
Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is slow-growing and can occur at any age.
Extranodal natural killer/T-cell lymphoma, nasal type is a rapidly evolving type of lymphoma that is very rare in Western countries but more common in Central Asia and South America. It is sometimes found on the skin, but can start elsewhere and affect the skin. People with this type of lymphoma are usually positive for the Epstein-Barr virus (EBV).
Primary cutaneous peripheral T-cell lymphoma, unspecified:
- Primary cutaneous CD4+ small/medium pleomorphic T-cell lymphoproliferative disorder is a slow-growing lymphoma with a good prognosis. It usually appears as a single plaque or nodule on the face, neck or upper torso.
- Primary cutaneous γ/δ T-cell lymphoma is a type of more rapidly developing cutaneous lymphoma that usually occurs in adults. It most often appears as patches or plaques on the upper and lower extremities and may be accompanied by night sweats, fever and weight loss.
- Primary cutaneous aggressive epidermotropic cytotoxic CD8+ T-cell lymphoma is a lymphoma that develops more rapidly and appears as extensive patches (bumps), plaques or tumors on the skin.