localization, and are highlighted in
this newsletter.
MATURE T-CELL AND
NK-CELL LEUKEMIAS
T-prolymphocytic leukemia (T-PLL)
T-large granular lymphocytic leuke
-
mia (T-LGLL)
Adult T-cell leukemia/lymphoma
(ATLL)
Aggressive NK-cell leukemia (ANKL)
Sezary syndrome
This group includes entities that
mostly present in a leukemic phase.
T-PLL requires monoclonal T-cell
lymphocytosis (> 5
×
10
9
/L), T-cell
monoclonality and aberrations in
TCL1A or MTCP1.
T-LGLL with STAT3 mutations is
associated with cytopenias, spleno
-
megaly and autoimmune diseases.
ATLL has shown new immune eva
-
sion mechanisms: CTLA4::CD28,
ICOS::CD28, REL truncations, varia
-
tions of CD274, and alterations in
HLA-A and HLA-B. ANKL is associ
-
ated with mutations in the JAK/
STAT pathway, epigenetic modiers
and immune checkpoints. Although
Sezary syndrome is much closer to
mycosis fungoides, it is discussed here
because of its leukemic presentation,
mimicking the other leukemic pro
-
cesses.
Issue 23 || June 2023
WHAT’S NEW IN
HEMATOPATHOLOGY
2023: UPDATES ON
MATURE T-CELL
NEOPLASMS IN THE 5TH
EDITION OF THE WHO
CLASSIFICATION
Mario L. Marques-Piubelli, MD
1
,
Roberto N. Miranda, MD
2
1
Department of Translational Molecular Pathology,
The University of Texas MD Anderson Cancer Center,
Houston, TX, USA
2
Department of Hematopathology, The University of
Texas MD Anderson Cancer Center, Houston, TX, USA
Corresponding Author: Roberto N. Miranda, MD
Department of Hematopathology, The University of
Texas MD Anderson Cancer Center, Houston, TX, USA
E-mail: roberto.miranda@mdanderson.org
ORCID
Mario L. Marques-Piubelli
https://orcid.org/0000-0002-6324-2096
Roberto N. Miranda
https://orcid.org/0000-0002-8467-5464
Abstract
The overview of the upcoming Blue
Book of the 5th edition of the World
Health Organization Classication of
Hematolymphoid Tumors was pub
-
lished in Leukemia in June 2022. The
updates on mature T-/NK-cell lym
-
phomas and leukemias are organized
in nine groups based on cell of origin,
morphology, clinical scenario, and
PRIMARY CUTANEOUS
T-CELL LYMPHOID
PROLIFERATIONS AND
LYMPHOMAS (CTCL)
Primary cutaneous CD4+ small or
medium T-cell lymphoproliferative
disorder
Primary cutaneous acral CD8+
lymphoproliferative disorder
Mycosis fungoides
Primary cutaneous CD30-positive
T-cell lymphoproliferative disorder:
lymphomatoid papulosis
Primary cutaneous CD30-positive
T-cell lymphoproliferative disorder:
primary cutaneous anaplastic large
cell lymphoma
Subcutaneous panniculitis-like
T-cell lymphoma
Primary cutaneous gamma/delta
T-cell lymphoma
Primary cutaneous CD8-positive
aggressive epidermotropic cytotoxic
T-cell lymphoma
Primary cutaneous peripheral T-cell
lymphoma (PTCL), NOS
These are well-known disorders as
noted in previous WHO editions, 9
in total. The most signicant change
is the removal of the umbrella term of
PTCL from which 4 different entities
have been derived, including PTCL,
NOS to emphasize that the CTCL are
still difcult to classify (Leukemia
2022;36:1720-1748). It is expected
WHAT’S NEW
IN PATHOLOGY?