DermNet provides Google Translate, a free machine translation service. Note that this may not provide an exact translation in all languages


Cutaneous T-cell lymphoma

Author: Vanessa Ngan, Staff Writer, 2006. DermNet Update May 2021. Further minor update June 2023.


What is cutaneous T-cell lymphoma?

Cutaneous T-cell lymphoma (CTCL) is the most common type of primary cutaneous lymphoma. It is a form of non-Hodgkin lymphoma in which malignant T-cells are initially localised to the skin with no evidence of extracutaneous disease at the time of diagnosis.

Cutaneous T-cell lymphoma

Who gets cutaneous T-cell lymphoma?

Cutaneous T-cell lymphoma comprises 4% of all non-Hodgkin lymphomas and 75-80% of all primary cutaneous lymphomas. It shows a male predominance of 2:1. The incidence of CTCL increases with age, with an average age at diagnosis of 50-60 years.

What causes cutaneous T-cell lymphoma?

The aetiopathogenesis of cutaneous T-cell lymphoma is unknown. Theories include a viral infection (eg, Epstein Barr virus, HTLV-1) causing a chronically heightened immune state, genetic changes (eg, HLA type), or chemical exposure (eg, medications).

Epigenetics regulates gene expression without altering the DNA sequence. Epigenetic studies of CTCL have identified changes in DNA methylation, histone modification, microRNAs and chromatin remodellers. One example is miR-155 which is overexpressed in malignant CTCL cells, especially in advanced stage disease, and treatments inhibiting this are in early clinical trials for tumour-stage mycosis fungoides, Sézary syndrome, and primary cutaneous anaplastic large-cell lymphoma.

An association between JAK inhibitors and malignancy (eg, T-cell lymphomas) is currently under investigation and is not fully understood. There have been rare cases of T-cell lymphomas reported in patients treated with JAK inhibitors, but the overall incidence appears to be low and causality has not been established.

What is the classification of cutaneous T-cell lymphomas?

The 2018 WHO-EORTC classification of cutaneous T-cell lymphomas is summarised in the following tables with links to specific DermNet webpages.

Table 1. Indolent forms of cutaneous T-cell lymphoma

Indolent forms of CTCL Frequency (%) Prognosis: 5 year survival (%)
Mycosis fungoides 39 88
Mycosis fungoides variants    
Folliculotropic MF 5 75
Pagetoid reticulosis <1 100
Granulomatous slack skin <1 100
Primary cutaneous CD30+ LPD    
pcALCL 8 95
Lymphomatoid papulosis 12 99
Primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder* 6 100
Subcutaneous panniculitis-like T-cell lymphoma 1 87

Table 2. Aggressive forms of cutaneous T-cell lymphoma

Aggressive forms of CTCL Frequency (%) Prognosis: 5 year survival (%)
Sézary syndrome 2 36
Adult T-cell leukaemia/lymphoma <1 NDA
Extranodal NK/T-cell lymphoma, nasal type <1 16
Chronic active EBV infection in childhood <1 NDA
Primary cutaneous
γ/δ T-cell lymphoma
<1 11
Primary cutaneous aggressive CD8+ lymphoma* <1 15
Primary cutaneous aggressive CD8+ cytotoxic T-cell lymphoma <1 31
Primary cutaneous peripheral T-cell lymphoma NOS 2 15

CTCL, cutaneous T-cell lymphoma; EBV, Epstein-Barr Virus; LPD, lymphoproliferative disorders; MF, mycosis fungoides; NDA, no data available; NK, natural killer cell; NOS, not otherwise specified; pcALCL, primary cutaneous anaplastic large-cell lymphoma; * provisional entities.

Adapted from: Willemze R, Cerroni L, Kempf W, et al. The 2018 update of the WHO-EORTC classification for primary cutaneous lymphomas. Blood. 2019;133(16):1703–14

Primary cutaneous small-medium pleomorphic T-cell lymphoma is an example of a ‘Primary cutaneous peripheral T-cell lymphoma NOS’ with an excellent prognosis.

What are the clinical features of cutaneous T-cell lymphomas?

Cutaneous T-cell lymphomas typically present as patches, papules, nodules, plaques, and/or tumours. Itch is reported by 80% of patients.

Patches, plaques, and tumours of cutaneous T-cell lymphomas

What are the complications of cutaneous T-cell lymphoma?

The diagnosis of cutaneous T-cell lymphoma is often delayed by months or years due to the indolent course, clinical similarity to inflammatory dermatoses, and subtle changes on histopathology.

Cutaneous T-cell lymphoma papules, nodules, and tumours may ulcerate and become necrotic, healing with varioliform scarring.

Extracutaneous spread affects 10%.

Quality of life can be significantly impacted due the economic burden of a chronic disease, or to symptoms such as itch and pain, psychological effects including anxiety and depression, and visible skin changes including hair loss.

Complications of cutaneous T-cell lymphoma

How is cutaneous T-cell lymphoma diagnosed?

Diagnosis of cutaneous T-cell lymphoma involves careful clinicopathological correlation. Multiple skin biopsies are often required to detect the characteristic histopathology changes, especially in the early patch stages. Further investigations may be performed on skin biopsy specimens including immunohistochemistry.

EBV, T-cell receptor (TCR) gene rearrangements, ALK, DUSP22-IRF4, and TP63 gene studies may be performed to confirm the diagnosis and predict the clinical course.

Enlarged lymph nodes may also be biopsied. Cutaneous T-cell lymphoma can cause harmless swelling, known as reactive or dermopathic lymphadenopathy, or malignant growth in the lymph nodes.

The blood count is normal in most patients with CTCL. An elevated white cell count is characteristic of Sézary syndrome and confirmed on flow cytometry. Some patients may require bone marrow biopsy.

Patients with advanced cutaneous T-cell lymphoma may undergo CT or MRI scans to determine whether the disease has affected internal organs.

Formal TNMB staging is recommended in some forms of CTCL.

What is the differential diagnosis for cutaneous T-cell lymphoma?

What is the treatment for cutaneous T-cell lymphoma?

Cutaneous T-cell lymphoma is regarded as treatable, not curable. Treatments considered will depend on the individual patient, specific type of CTCL, stage of disease, local expertise, and available drugs and equipment. There are no global consensus guidelines for treating CTCL.

Topical treatment

Skin-directed topical treatments are the mainstay of early disease.

Procedural treatment

Systemic treatment

What is the outcome for cutaneous T-cell lymphoma?

Cutaneous T-cell lymphoma typically follows a long slow course remaining confined to the skin, progressing over many years, and not usually life-threatening.

Some forms of CTCL progress more rapidly with a minority developing advanced disease including tumour formation, extracutaneous spread (10%), and progression to systemic lymphoma.



  • Alpdogan O, Kartan S, Johnson W, Sokol K, Porcu P. Systemic therapy of cutaneous T-cell lymphoma (CTCL). Chin Clin Oncol. 2019;8(1):10. doi:10.21037/cco.2019.01.02. Journal
  • Kohnken R, Mishra A. MicroRNAs in Cutaneous T-cell lymphoma: the future of therapy. J Invest Dermatol. 2019;139(3):528–34. doi:10.1016/j.jid.2018.10.035. Journal
  • Kołkowski K, Trzeciak M, Sokołowska-Wojdyło M. Safety and Danger Considerations of Novel Treatments for Atopic Dermatitis in Context of Primary Cutaneous Lymphomas. Int J Mol Sci. 2021;22(24):13388. Published 2021 Dec 13. doi:10.3390/ijms222413388 Journal
  • Kandai Saito and others, A case of Sézary syndrome in a patient during treatment with baricitinib for seronegative rheumatoid arthritis, Clinical and Experimental Dermatology, Volume 48, Issue 4, April 2023. Journal
  • Lai P, Wang Y. Epigenetics of cutaneous T-cell lymphoma: biomarkers and therapeutic potentials. Cancer Biol Med. 2021;18(1):34–51. doi:10.20892/j.issn.2095-3941.2020.0216. PubMed Central
  • Peterson E, Weed J, Lo Sicco K, Latkowski JA. Cutaneous T cell lymphoma: a difficult diagnosis demystified. Dermatol Clin. 2019;37(4):455–69. doi:10.1016/j.det.2019.05.007. PubMed
  • Pulitzer M. Cutaneous T-cell lymphoma. Clin Lab Med. 2017;37(3):527–46. doi:10.1016/j.cll.2017.06.006. PubMed Central
  • Scarisbrick JJ, Bagot M, Ortiz-Romero PL. The changing therapeutic landscape, burden of disease, and unmet needs in patients with cutaneous T-cell lymphoma. Br J Haematol. 2021;192(4):683–96. doi:10.1111/bjh.17117. Journal
  • Wilcox RA. Cutaneous T-cell lymphoma: 2017 update on diagnosis, risk-stratification, and management. Am J Hematol. 2017;92(10):1085–102. doi:10.1002/ajh.24876. Journal
  • Willemze R, Cerroni L, Kempf W, et al. The 2018 update of the WHO-EORTC classification for primary cutaneous lymphomas. Blood. 2019;133(16):1703–14. doi:10.1182/blood-2018-11-881268. Journal

On DermNet

Other websites

Books about skin diseases


Related information

Sign up to the newsletter