Cutaneous T-Cell Lymphoma (CTCL) as the name suggests is a type of lymphoma in which T-cells accumulate in the skin. The reason for this is because the T-cells involved are the ones which normally patrol the skin.
The skin is the second most common extranodal site for lymphoma; gastrointestinal sites are first. Of all primary cutaneous lymphomas, 65% are of the T-cell type. The most common immunophenotype is CD4 positive.
A diagnosis of CTCL is not in itself a final diagnosis. It comes in a variety of forms which have a different prognosis, and different behaviour and response to treatment. Below is information about the primary type (MF/SS) but other types appear on the menu at the left.
MF/SS is a very difficult disease to diagnose. In the early stages it usually presents as a skin rashes consisting of patches, plaques or tumours. Even when a biopsy is done at this stage it often will not show MF/SS and is often identified as a benign skin condition. On average, when discovered in the early stages it will take up to six years to obtain a final diagnosis. Repeated biopsies will frequently yield no diagnosis. This is why it is often not diagnosed until the later stages. (not unlike many other indolent varieties of lymphoma)
MF/SS is the most common of all the CTCL's and represents about 40% of the total. Sézary syndrome (SS) is a variant of MF in which the cancer has spread to the circulating blood. This only occurs in about 5% of all cases of MF, and is generally associated with a poorer prognosis.
Long term survival prognosis for MF/SS depends largely on the stage at diagnosis. Early stage patients have good prospects for survival of 20 years or more. (3) Those who present at late stage disease have poor prognosis for 5 year survival. Presently there is no prognostic index as there is for more common types of lymphoma. However the Severity Weighted Assessment Tool (SWAT) or its modification, the mSWAT are used to access the probably response to treatment (4).
There is no consensus on the optimal treatment for MF/SS. Treatment will largely be dependent upon the severity of the disease. However in general it is recognized that systemic chemotherapy is not as effective as skin directed therapies, such as corticosteroid cream, psoralen plus UVA radiation, UVB phototherapy, or local radiation. After that non-chemotherapy options may be a better option. This includes but is not limited to alpha interferon, bexarotene, histone deacetylase inhibitors, monoclonal antibodies, fusion toxins, and extracorporal photopheresis. (5)(6)
There are 2 new therapies which are showing great promise. SGX301 has received orphan drug designation in both the United States and the European Union. This novel photodynamic therapy is applied to the skin. Exposure to normal fluorescent light then activates it. (7) (8) This is in contrast to other photodynamic therapies which require exposure to ultraviolet light.
The second is Topical resiquimod . This drug is showing early results that are quite impressive, though they still have to be validated. (9) This treatment is still in very early trials, but if the results pan out it could prove to be a more effective therapy than current options.
Other Mycosis Fungoides / Sézary Syndrome resources. The first link is from an expert in the field (not this webmaster)
Clinical End Points and Response Criteria in Mycosis Fungoides and Sézary Syndrome: A Consensus Statement of the International Society for Cutaneous Lymphomas, the United States Cutaneous Lymphoma Consortium, and the Cutaneous Lymphoma Task Force of the European Organisation for Research and Treatment of Cancer