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Health condition · Clinically reviewed

Cutaneous T-cell lymphoma, a slow-moving skin lymphoma with a modern treatment ladder.

Mycosis fungoides, Sezary syndrome and the CD30-positive disorders behave differently, and are treated differently. This guide explains what CTCL is, how it is staged and what UK care looks like in 2026.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against BAD, EORTC/ISCL and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice including brentuximab vedotin, mogamulizumab and extracorporeal photopheresis.

Key facts

CTCL at a glance.

The essentials, in plain English. What CTCL is, the main subtypes, and how it is diagnosed and treated in the UK today.

  • What it is

    A group of non-Hodgkin lymphomas of skin-homing T-cells. The commonest form is mycosis fungoides, an indolent lymphoma that can evolve over decades.

  • How common

    CTCL is the commonest primary cutaneous lymphoma, accounting for about three-quarters of all skin lymphomas. Peak onset is in the mid-fifties, with a male predominance of about 2:1.

  • Main subtypes

    Mycosis fungoides (about 50 to 60 per cent of CTCL), Sezary syndrome, CD30-positive lymphoproliferative disorders (lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma), and rare entities.

  • How it presents

    Patch, plaque, tumour and erythrodermic stages of mycosis fungoides. Sezary syndrome adds erythroderma, intense itch and circulating malignant T-cells.

  • How it is diagnosed

    Repeated skin biopsies with immunohistochemistry and T-cell receptor clonality, staged using the TNMB system with bloods, flow cytometry and imaging.

  • How it is treated

    Skin-directed therapy for early disease, systemic therapy and photopheresis for advanced disease, and allogeneic stem cell transplant for selected young, fit patients.

Why this guide matters

A rare diagnosis, a well-mapped pathway.

CTCL is uncommon and often confused with eczema or psoriasis. The three points below shape everything else on this page.

  • Subtype and stage drive everything

    Mycosis fungoides, Sezary syndrome and the CD30-positive disorders have very different courses. The TNMB stage sets the treatment ladder.

  • Early disease is often skin-directed

    For patches and plaques, potent topical steroids, narrowband UVB and PUVA can control disease for years without systemic drugs.

  • Modern systemic therapy has changed the picture

    Brentuximab vedotin, mogamulizumab and extracorporeal photopheresis give real options in advanced disease, alongside careful supportive care.

How the diagnosis is made

From a persistent rash to a clear stage and plan.

The steps a UK dermatology and skin lymphoma team will normally follow, in order, so you know what to expect and why.

  1. 01

    Assessing

    Dermatology review

    A specialist skin examination looking for patches, plaques, tumours or erythroderma, and mapping the body-surface area involved.

  2. 02

    Assessing

    Multiple skin biopsies

    Representative biopsies from several sites, often repeated over time, are needed. Early CTCL can mimic eczema or psoriasis and diagnosis is frequently delayed for years.

  3. 03

    Assessing

    Specialist dermatopathology

    Immunohistochemistry for CD3, CD4, CD8, CD5, CD7 and CD30 with molecular T-cell receptor clonality, reviewed by a lymphoma-experienced dermatopathologist.

  4. 04

    Confirming

    Bloods and flow cytometry

    Full blood count, LDH, liver function, peripheral blood smear and beta-2 microglobulin. Flow cytometry looks for a Sezary cell clone in blood.

  5. 05

    Confirming

    Lymph node assessment

    Palpable nodes are examined and, if enlarged, biopsied. This helps assign the N stage in the TNMB system.

  6. 06

    Planning

    Imaging for advanced stages

    CT or PET-CT is used in tumour-stage, erythrodermic or high-B stage disease. Bone marrow biopsy is selective, not routine.

  7. 07

    Planning

    Skin lymphoma MDT

    Cases are discussed at a specialist skin lymphoma multidisciplinary team meeting, which sets stage, prognosis and a personalised treatment plan.

Typical timeline: initial biopsies and staging complete within weeks of specialist referral.

Symptoms

What CTCL actually looks like.

The classic mycosis fungoides progression from patch to plaque to tumour, plus erythroderma, Sezary features and the CD30-positive presentations.

  • Patch stage

    Flat, red, scaly patches, often on sun-protected sites such as the buttock, trunk or intertriginous areas. Can be mistaken for eczema for years.

  • Plaque stage

    Thicker, infiltrated, sometimes annular or polymorphic plaques that persist and slowly extend.

  • Tumour stage

    Firm nodules or ulcerating tumours arising within existing plaques or on previously normal skin.

  • Erythroderma

    Confluent redness affecting more than eighty per cent of the skin, with intense pruritus, scaling and heat loss.

  • Sezary features

    Erythroderma plus palmoplantar keratoderma, alopecia, ectropion, lymphadenopathy and circulating Sezary cells above 1,000 per microlitre.

  • Folliculotropic variant

    Follicular papules, alopecia patches and acneiform lesions, most often on the head and neck. Behaves more aggressively than classic mycosis fungoides.

  • CD30-positive lesions

    Lymphomatoid papulosis produces crops of self-healing papules and nodules. Primary cutaneous ALCL presents as one or a few larger nodules with a good prognosis.

  • Red flag - relentless itch

    Severe, unremitting itch, night sweats, weight loss or new lumps in a patient with known CTCL warrant urgent specialist review.

Treatment

How CTCL is treated in the UK.

Skin-directed therapy for early disease, systemic therapy and photopheresis for advanced disease, with allogeneic stem cell transplant reserved for selected patients.

  • Topical corticosteroids

    Potent and very potent topical steroids are first-line for early patch and plaque mycosis fungoides, used under specialist guidance.

  • Narrowband UVB phototherapy

    Delivered in a specialist phototherapy clinic, narrowband UVB is highly effective for patch and plaque disease. See our phototherapy clinic page.

  • PUVA (psoralen plus UVA)

    Combines an oral or topical psoralen with UVA light, used for thicker plaques and tumour-stage disease when UVB is insufficient.

  • Topical nitrogen mustard

    Mechlorethamine gel is applied to affected skin for early-stage disease when steroids and phototherapy are not enough.

  • Topical retinoid

    Bexarotene gel is used for localised, refractory patches and plaques under specialist supervision.

  • Local radiotherapy

    Doses of about 8 to 30 Gy give excellent local control of tumours and thick plaques, especially in older or frailer patients.

  • Total skin electron beam therapy

    A highly specialised radiotherapy technique for extensive tumour or erythrodermic disease. Delivered at a small number of UK centres including Guy’s, the Christie and the Beatson.

  • Bexarotene (oral retinoid)

    Often the first systemic option for advanced CTCL. Requires monitoring of lipids and thyroid function.

  • Interferon alpha

    A long-established systemic option, sometimes combined with PUVA for erythrodermic disease.

  • Low-dose methotrexate

    A weekly oral or subcutaneous option for refractory plaque or erythrodermic CTCL.

  • Extracorporeal photopheresis

    ECP treats the patient’s own blood with UVA light after 8-methoxypsoralen. Particularly useful in Sezary syndrome and erythrodermic MF. See our ECP photopheresis clinic page.

  • HDAC inhibitors

    Vorinostat and romidepsin are used in advanced disease, with specialist monitoring for cytopenias and cardiac effects.

  • Brentuximab vedotin

    An anti-CD30 antibody-drug conjugate approved for CD30-positive CTCL. See our brentuximab clinic page.

  • Mogamulizumab

    An anti-CCR4 antibody licensed for mycosis fungoides and Sezary syndrome after at least one prior systemic therapy. See our mogamulizumab clinic page.

  • Chemotherapy

    Options such as gemcitabine and liposomal doxorubicin are reserved for advanced or transformed disease.

  • Allogeneic stem cell transplant

    The only potentially curative option, offered to selected younger, fit patients with advanced disease. See our stem cell transplant page.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, European consensus statements and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your dermatologist, haematologist or skin lymphoma team knows your case and can tell you which parts apply to you. If in doubt, get seen.

  • British Association of Dermatologists (BAD). Guidelines for the management of primary cutaneous lymphomas.

  • EORTC/ISCL. Consensus statements on staging and treatment of mycosis fungoides and Sezary syndrome.

  • WHO-EORTC 2018 classification of cutaneous lymphomas.

  • NICE technology appraisals for brentuximab vedotin and mogamulizumab in CTCL.

  • Lymphoma Action and the Cutaneous Lymphoma Foundation patient information.

Red flags

When CTCL needs urgent attention.

Much of CTCL follows a stable course, but these situations need same-day or same-week specialist input.

  • Rapid transformation

    Sudden appearance of tumours or ulceration in previously stable plaques can signal large-cell transformation and needs urgent MDT review.

  • New erythroderma

    Widespread redness of more than eighty per cent of the skin with intense itch may indicate progression to Sezary syndrome or erythrodermic MF.

  • Uncontrolled pruritus

    Itch that disturbs sleep and daily life despite emollients, antihistamines and gabapentin or pregabalin deserves an early clinic review.

  • Systemic B symptoms

    Unexplained fevers, drenching night sweats and weight loss of more than ten per cent suggest advanced disease and need staging investigations.

  • New lymphadenopathy

    Persistent, enlarging or firm lymph nodes should be assessed, and often biopsied, to reclassify the N stage.

  • Skin infection or sepsis

    Erythrodermic and heavily treated skin is prone to Staphylococcus aureus infection, cellulitis and, occasionally, sepsis. Fever with new redness needs urgent care.

  • Second malignancy

    Patients with CTCL have a higher long-term risk of other skin cancers and lymphomas. Any new skin lesion or lump warrants prompt review.

  • Mood and quality of life

    Visible skin disease, chronic itch and a serious diagnosis carry a real mental-health burden. Low mood or suicidal thoughts need urgent GP or crisis support.

  • Treatment toxicity

    New cytopenias, infections, cardiac symptoms or severe skin reactions on systemic therapy should be reported to the treating team the same day.

Living with it

A long-term diagnosis, with real support.

Four things that make the biggest difference day to day. Daily skin care, layered itch relief, specialist support and long-term surveillance.

A quiet reminder

Small, steady habits beat heroic weeks.

Consistent emollient use, sleep, sun protection and follow-up appointments do more, over time, than any single intervention.

  1. 01 Skin care

    Emollients are non-negotiable

    Generous, daily use of bland emollients calms itch, protects the barrier and reduces the need for topical steroids.

  2. 02 Itch

    Layer itch relief

    Antihistamines, gabapentin or pregabalin and, at times, low-dose antidepressants can be combined by your team to make itch bearable.

  3. 03 Support

    Specialist nursing and charities

    Skin lymphoma clinical nurse specialists, Lymphoma Action and the Cutaneous Lymphoma Foundation offer practical and emotional support alongside the medical team.

  4. 04 Follow-up

    Long-term surveillance

    Regular skin, blood and imaging reviews watch for progression, treatment side effects and second cancers, especially other skin cancers.

Frequently asked

Everything we get asked about CTCL.

Quick answers on subtypes, staging, skin-directed therapy, systemic options and prognosis.

  • What is cutaneous T-cell lymphoma?

    CTCL is a group of non-Hodgkin lymphomas in which malignant T-cells home to the skin. The commonest subtype is mycosis fungoides, an indolent disease that can evolve over decades. Sezary syndrome is a leukaemic, more aggressive form with erythroderma and circulating malignant T-cells.

  • Why is CTCL often diagnosed late?

    Early patch and plaque disease can look and feel like eczema or psoriasis for years. Diagnosis usually requires multiple, repeated skin biopsies interpreted by specialist dermatopathologists, together with immunohistochemistry and molecular T-cell receptor clonality.

  • How is CTCL staged?

    CTCL is staged using the TNMB system, which describes the extent of skin (T), lymph node (N), visceral (M) and blood (B) involvement. Staging uses a full skin exam, blood tests, flow cytometry and, in more advanced disease, CT or PET-CT and sometimes a bone marrow biopsy.

  • What does skin-directed treatment involve?

    For early mycosis fungoides, treatment is aimed at the skin. Options include potent topical steroids, narrowband UVB, PUVA, topical nitrogen mustard, topical bexarotene and localised radiotherapy. Many patients live for decades with skin-directed therapy alone.

  • What systemic treatments are used for advanced CTCL?

    Advanced or refractory disease may be treated with oral bexarotene, interferon alpha, low-dose methotrexate, extracorporeal photopheresis, HDAC inhibitors, brentuximab vedotin for CD30-positive disease and mogamulizumab for mycosis fungoides or Sezary syndrome. Chemotherapy and allogeneic stem cell transplant are reserved for selected patients.

  • What is the outlook?

    Prognosis depends heavily on subtype and stage. Early-stage mycosis fungoides often has near-normal life expectancy. Sezary syndrome and advanced-stage disease have a poorer outlook, with median survival of about three to four years, though newer therapies are improving these figures. Every plan is individualised at the skin lymphoma MDT.

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