Part of Cancer staging guidance sheets
Mycosis fungoides or sezary syndrome (ICD10 C84.0 and C84.1)
Introduction
This is the data sheet for TNM 9th edition staging of mycosis fungoides or sezary syndrome (ICD10 C84.0 and C84.1)
For more detailed information regarding TNM staging, please see pages 234-236 of the UICC TNM 9 book.
Group staging
Mycosis fungoides or sezary syndrome
|
Prognostic group |
T stage |
N stage |
M stage |
Peripheral blood involvement |
|---|---|---|---|---|
|
IA |
T1 |
N0 |
M0 |
B0, B1 |
|
IB |
T2 |
N0 |
M0 |
B0, B1 |
|
IIA |
T1, T2 |
N1, N2 |
M0 |
B0, B1 |
|
IIB |
T3 |
N0, N1, N2 |
M0 |
B0, B1 |
|
III |
T4 |
N0, N1, N2 |
M0 |
B0, B1 |
|
IIIA |
T4 |
N0, N1, N2 |
M0 |
B0 |
|
IIIB |
T4 |
N0, N1, N2 |
M0 |
B1 |
|
IVA1 |
Any T |
N0, N1, N2 |
M0 |
B2 |
|
IVA2 |
Any T |
N3 |
M0 |
Any B |
|
IVB |
Any T |
Any N |
M1 |
Any B |
Notes:
This is a prognostic group as the prognostic group is determined by the absence or presence of peripheral blood involvement. Clone status is not required to assign a prognostic group.
TNM clinical classification
Mycosis fungoides or sezary syndrome
T - primary tumour
|
T value |
Description |
|---|---|
|
T1 |
Limited patches. papules, and/or plaques covering < 10% of the skin surface T1a – Patch only T1b – Plaque/papule ± patch |
|
T2 |
Patches, papules, or plaques covering ≥ 10% of the skin surface T2a – Patch only T2b – Plaque/papule ± patch |
|
T3 |
One or more tumours (≥1 cm in diameter) |
|
T4 |
Confluence of erythema covering ≥80% of the body surface |
N - regional lymph nodes
|
N value |
Description |
|---|---|
|
NX |
Clinically abnormal peripheral lymph nodes, no histologic confirmation |
|
N0 |
No clinically abnormal peripheral lymph nodes*, biopsy not required |
|
N1 |
Clinically abnormal peripheral lymph nodes; histopathology Dutch grade 1 or National Cancer Institute (NCI) LN0-2 N1a – Clone negative** or equivocal N1b – Clone positive** and identical to skin |
|
N2 |
Clinically abnormal peripheral lymph nodes; histopathology Dutch grade 2 or NCI LN3 N2a - Clone negative** or equivocal N2b - Clone positive** and identical to skin |
|
N3 |
Clinically abnormal peripheral lymph nodes; histopathology Dutch grades 3-4 or NCI LN4 N3a - Clone negative** or equivocal N3b - Clone positive** and identical to skin |
Note
* A lymph node (LN) of >1.5 cm in the longest diameter (LDi) is considered abnormal, especially if accompanied by other features of concern (firm, rubbery and/or fixed) but should be confirmed by imaging. Central nodes, which generally are not amenable to pathological assessment, currently are not considered in the nodal classification unless used to establish N3 histopathologically.
** A T cell clone is defined by polymerase chain reaction (PCR) or Southern blot analysis of the TCR genes
M - distant metastasis
|
M value |
Description |
|---|---|
|
M0 |
No visceral organ involvement* |
|
M1a |
Bone marrow only M1a1 - Clone negative** or equivocal M1a2 – Clone positive** and identical to skin |
|
M1b |
Non-bone marrow visceral involvement* with or without bone marrow involvement M1a1 - Clone negative** or equivocal M1a2 – Clone positive** and identical to skin |
* For viscera, spleen and liver may be diagnosed by imaging criteria
** A T cell clone is defined by polymerase chain reaction (PCR) or Southern blot analysis of the TCR genes.
Histopathologic staging of lymph nodes in Mycosis Fungoides and Sezary syndrome
|
EORTC classification |
Dutch system |
NCI-VA classification |
|---|---|---|
|
N1 |
Grade 1: Dermatopathic lymphadenopathy (DL) |
LN0: No atypical lymphoctyes LN1: Occasional and isolated Atypical Lymphocytes (not arranged in clusters) LN2: Many atypical lymphocytes in 3-6 cell clusters |
|
N2 |
Grade 2: DL; early involvement b MF (presence of cerebriform nuclei <7.5 µm) |
LN3: Aggregates of atypical lymphocytes; nodal architecture preserved. |
|
N3 |
Grade 3: partial effacement of lymph node architecture; many atypical cerebriform architecture by atypical lymphocytes mononuclear cells Grade 4: complete effacement |
LN4: Partial/complete effacement of nodal or frankly neoplastic cells |
Peripheral blood involvement (B)
|
B category |
B criteria |
|---|---|
|
B0 |
Absence of significant blood involvement: ≤250/µL of CD4+/CD26- or CD4+/CD7- cells B0a – Clone negative** B0b – Clone positive** |
|
B1 |
Low blood tumour burden: >250/µL but ≤1000/µL of CD4+/CD26- or CD4+/CD7- cells B1a – Clone negative** B1b – Clone positive** |
|
B2 |
High blood tumour burden: >1000/µL of CD4+/CD26- or CD4+/CD7- cells or other aberrant population of lymphocytes identified by flow cytometry. |
** A T cell clone is defined by polymerase chain reaction (PCR) or Southern blot analysis of the TCR genes
Last edited: 16 January 2026 4:03 pm
