Abstract

The term “unexplained cytopenia” is used to describe a condition characterized by peripheral blood cytopenia that cannot be attributed to identifiable causes using conventional tests or to any concomitant diseases. Unexplained cytopenia requires clinical attention and further investigation to identify individuals at risk of developing a hematologic neoplasm. The available evidence suggests that somatic mutation analysis may effectively complement the diagnostic workup and clinical management of unexplained cytopenia. Indeed, the presence or absence of somatic mutation(s) in myeloid genes shows high positive and negative predictive values for myeloid neoplasms (MNs). Mutation analysis is also crucial for identifying patients with clonal cytopenia of undetermined significance (CCUS), a condition at increased risk of developing a MN. Recently, clinical/molecular prognostic models have been developed, providing valuable tools for the personalization of clinical and molecular surveillance. Most patients with CCUS show mild cytopenia and do not require therapeutic intervention. Currently, there is no treatment approved for CCUS, and transfusion therapy is the sole therapeutic option for patients with severe symptomatic cytopenia. However, this field has been emerging as a domain of active clinical investigation. This article presents 4 case studies of patients with unexplained cytopenia, which hematologists may encounter in their clinical practice.

1.
Guralnik
JM
,
Eisenstaedt
RS
,
Ferrucci
L
,
Klein
HG
,
Woodman
RC
.
Prevalence of anemia in persons 65 years and older in the United States: evidence for a high rate of unexplained anemia
.
Blood
.
2004
;
104
(
8
):
2263
-
2268
.
2.
van Zeventer
IA
,
de Graaf
AO
,
van der Klauw
MM
, et al
.
Peripheral blood cytopenias in the aging general population and risk of incident hematological disease and mortality
.
Blood Adv
.
2021
;
5
(
17
):
3266
-
3278
.
3.
Patel
KV
,
Harris
TB
,
Faulhaber
M
, et al
.
Racial variation in the relationship of anemia with mortality and mobility disability among older adults
.
Blood
.
2007
;
109
(
11
):
4663
-
4670
.
4.
Riva
E
,
Tettamanti
M
,
Mosconi
P
, et al
.
Association of mild anemia with hospitalization and mortality in the elderly: the health and anemia population-based study
.
Haematologica
.
2009
;
94
(
1
):
22
-
28
.
5.
Malcovati
L
,
Hellstrom-Lindberg
E
,
Bowen
D
, et al
.
Diagnosis and treatment of primary myelodysplastic syndromes in adults: recommendations from the European LeukemiaNet
.
Blood
.
2013
;
122
(
17
):
2943
-
2964
.
6.
Cazzola
M
.
Myelodysplastic syndromes
.
N Engl J Med
.
2020
;
383
(
14
):
1358
-
1374
.
7.
Valent
P
,
Horny
HP
,
Bennett
JM
, et al
.
Definitions and standards in the diagnosis and treatment of the myelodysplastic syndromes: consensus statements and report from a working conference
.
Leuk Res
.
2007
;
31
(
6
):
727
-
736
.
8.
Valent
P
,
Horny
HP
.
Minimal diagnostic criteria for myelodysplastic syndromes and separation from ICUS and IDUS: update and open questions
.
Eur J Clin Invest
.
2009
;
39
(
7
):
548
-
553
.
9.
Arber
DA
,
Orazi
A
,
Hasserjian
RP
, et al
.
International Consensus Classification of myeloid neoplasms and acute leukemias: integrating morphologic, clinical, and genomic data
.
Blood
.
2022
;
140
(
11
):
1200
-
1228
.
10.
Khoury
JD
,
Solary
E
,
Abla
O
, et al
.
The 5th edition of the World Health Organization Classification of haematolymphoid tumours: myeloid and histiocytic/dendritic neoplasms
.
Leukemia
.
2022
;
36
(
7
):
1703
-
1719
.
11.
Beck
DB
,
Ferrada
MA
,
Sikora
KA
, et al
.
Somatic mutations in UBA1 and severe adult-onset autoinflammatory disease
.
N Engl J Med
.
2020
;
383
(
27
):
2628
-
2638
.
12.
Fioredda
F
,
Skokowa
J
,
Tamary
H
, et al
.
The European guidelines on diagnosis and management of neutropenia in adults and children: a consensus between the European Hematology Association and the EuNet-INNOCHRON COST action
.
Hemasphere
.
2023
;
7
(
4
):
e872
.
13.
Duncavage
EJ
,
Bagg
A
,
Hasserjian
RP
, et al
.
Genomic profiling for clinical decision making in myeloid neoplasms and acute leukemia
.
Blood
.
2022
;
140
(
21
):
2228
-
2247
.
14.
Cazzola
M
,
Malcovati
L
.
Genome sequencing in the management of myelodysplastic syndromes and related disorders
.
Haematologica
.
2025
;
110
(
2
):
312
-
329
.
15.
Kwok
B
,
Hall
JM
,
Witte
JS
, et al
.
MDS-associated somatic mutations and clonal hematopoiesis are common in idiopathic cytopenias of undetermined significance
.
Blood
.
2015
;
126
(
21
):
2355
-
2361
.
16.
Cargo
CA
,
Rowbotham
N
,
Evans
PA
, et al
.
Targeted sequencing identifies patients with preclinical MDS at high risk of disease progression
.
Blood
.
2015
;
126
(
21
):
2362
-
2365
.
17.
Steensma
DP
,
Bejar
R
,
Jaiswal
S
, et al
.
Clonal hematopoiesis of indeterminate potential and its distinction from myelodysplastic syndromes
.
Blood
.
2015
;
126
(
1
):
9
-
16
.
18.
Malcovati
L
,
Galli
A
,
Travaglino
E
, et al
.
Clinical significance of somatic mutation in unexplained blood cytopenia
.
Blood
.
2017
;
129
(
25
):
3371
-
3378
.
19.
Steensma
DP
.
How I use molecular genetic tests to evaluate patients who have or may have myelodysplastic syndromes
.
Blood
.
2018
;
132
(
16
):
1657
-
1663
.
20.
Cargo
C
,
Cullen
M
,
Taylor
J
, et al
.
The use of targeted sequencing and flow cytometry to identify patients with a clinically significant monocytosis
.
Blood
.
2019
;
133
(
12
):
1325
-
1334
.
21.
Malcovati
L
,
Cazzola
M
.
The shadowlands of MDS: idiopathic cytopenias of undetermined significance (ICUS) and clonal hematopoiesis of indeterminate potential (CHIP)
.
Hematology Am Soc Hematol Educ Program
.
2015
;
2015
(
1
):
299
-
307
.
22.
Gorak
EJ
,
Otterstatter
M
,
Al Baghdadi
T
, et al
.
Discordant pathologic diagnoses of myelodysplastic neoplasms and their implications for registries and therapies
.
Blood Adv
.
2023
;
7
(
20
):
6120
-
6129
.
23.
DeZern
AE
,
Goll
JB
,
Lindsley
RC
, et al
.
Utility of targeted gene sequencing to differentiate myeloid malignancies from other cytopenic conditions
.
Blood Adv
.
2023
;
7
(
14
):
3749
-
3759
.
24.
Hasserjian
RP
,
Germing
U
,
Malcovati
L
.
Diagnosis and classification of myelodysplastic syndromes
.
Blood
.
2023
;
142
(
26
):
2247
-
2257
.
25.
Bono
E
,
McLornan
D
,
Travaglino
E
, et al
.
Clinical, histopathological and molecular characterization of hypoplastic myelodysplastic syndrome
.
Leukemia
.
2019
;
33
(
10
):
2495
-
2505
.
26.
Molteni
E
,
Bono
E
,
Galli
A
, et al
.
Prevalence and clinical expression of germ line predisposition to myeloid neoplasms in adults with marrow hypocellularity
.
Blood
.
2023
;
142
(
7
):
643
-
657
.
27.
Bernard
E
,
Hasserjian
RP
,
Greenberg
PL
, et al
.
Molecular taxonomy of myelodysplastic syndromes and its clinical implications
.
Blood
.
2024
;
144
(
15
):
1617
-
1632
.
28.
Sirenko
M
,
Bernard
E
,
Creignou
M
, et al
.
Molecular and clinical presentation of UBA1-mutated myelodysplastic syndromes
.
Blood
.
2024
;
144
(
11
):
1221
-
1229
.
29.
Galli
A
,
Todisco
G
,
Catamo
E
, et al
.
Relationship between clone metrics and clinical outcome in clonal cytopenia
.
Blood
.
2021
;
138
(
11
):
965
-
976
.
30.
Cargo
C
,
Bernard
E
,
Beinortas
T
, et al
.
Predicting cytopenias, progression, and survival in patients with clonal cytopenia of undetermined significance: a prospective cohort study
.
Lancet Haematol
.
2024
;
11
(
1
):
e51
-
e61
.
31.
Tsaknakis
G
,
Galli
A
,
Papadakis
S
, et al
.
Incidence and prognosis of clonal hematopoiesis in patients with chronic idiopathic neutropenia
.
Blood
.
2021
;
138
(
14
):
1249
-
1257
.
32.
van Zeventer
IA
,
de Graaf
AO
,
Wouters
H
, et al
.
Mutational spectrum and dynamics of clonal hematopoiesis in anemia of older individuals
.
Blood
.
2020
;
135
(
14
):
1161
-
1170
.
33.
Dharan
NJ
,
Yeh
P
,
Bloch
M
, et al
.
HIV is associated with an increased risk of age-related clonal hematopoiesis among older adults
.
Nat Med
.
2021
;
27
(
6
):
1006
-
1011
.
34.
Bick
AG
,
Popadin
K
,
Thorball
CW
, et al
.
Increased prevalence of clonal hematopoiesis of indeterminate potential amongst people living with HIV
.
Sci Rep
.
2022
;
12
(
1
):
577
.
35.
Yoshizato
T
,
Dumitriu
B
,
Hosokawa
K
, et al
.
Somatic mutations and clonal hematopoiesis in aplastic anemia
.
N Engl J Med
.
2015
;
373
(
1
):
35
-
47
.
36.
Gurnari
C
,
Pagliuca
S
,
Prata
PH
, et al
.
Clinical and molecular determinants of clonal evolution in aplastic anemia and paroxysmal nocturnal hemoglobinuria
.
J Clin Oncol
.
2023
;
41
(
1
):
132
-
142
.
37.
van Zeventer
IA
,
de Graaf
AO
,
Koorenhof-Scheele
TN
, et al
.
Monocytosis and its association with clonal hematopoiesis in community-dwelling individuals
.
Blood Adv
.
2022
;
6
(
14
):
4174
-
4184
.
38.
Lucas
F
,
Michaels
PD
,
Wang
D
,
Kim
AS
.
Mutational analysis of hematologic neoplasms in 164 paired peripheral blood and bone marrow samples by next-generation sequencing
.
Blood Adv
.
2020
;
4
(
18
):
4362
-
4365
.
39.
Sandmann
S
,
de Graaf
AO
,
Tobiasson
M
, et al
.
Multicenter next-generation sequencing studies between theory and practice: harmonization of data analysis using real-world myelodysplastic syndrome data
.
J Mol Diagn
.
2021
;
23
(
3
):
347
-
357
.
40.
Jansko-Gadermeir
B
,
Leisch
M
,
Gassner
FJ
, et al
.
Myeloid NGS analyses of paired samples from bone marrow and peripheral blood yield concordant results: a prospective cohort analysis of the AGMT Study Group
.
Cancers
.
2023
;
15
(
8
):
2305
.
41.
Radakovich
N
,
Meggendorfer
M
,
Malcovati
L
, et al
.
A geno-clinical decision model for the diagnosis of myelodysplastic syndromes
.
Blood Adv
.
2021
;
5
(
21
):
4361
-
4369
.
42.
Oster
HS
,
Crouch
S
,
Smith
A
, et al
.
A predictive algorithm using clinical and laboratory parameters may assist in ruling out and in diagnosing MDS
.
Blood Adv
.
2021
;
5
(
16
):
3066
-
3075
.
43.
Goldberg
SL
,
Chen
E
,
Corral
M
, et al
.
Incidence and clinical complications of myelodysplastic syndromes among United States Medicare beneficiaries
.
J Clin Oncol
.
2010
;
28
(
17
):
2847
-
2852
.
44.
Cogle
CR
,
Craig
BM
,
Rollison
DE
,
List
AF
.
Incidence of the myelodysplastic syndromes using a novel claims-based algorithm: high number of uncaptured cases by cancer registries
.
Blood
.
2011
;
117
(
26
):
7121
-
7125
.
45.
Weeks
LD
,
Niroula
A
,
Neuberg
D
, et al
.
Prediction of risk for myeloid malignancy in clonal hematopoiesis
.
NEJM Evid
.
2023
;
2
(
5
):
10.1056/evidoa2200310
.
46.
Gu
M
,
Kovilakam
SC
,
Dunn
WG
, et al
.
Multiparameter prediction of myeloid neoplasia risk
.
Nat Genet
.
2023
;
55
(
9
):
1523
-
1530
.
47.
Xie
Z
,
Komrokji
R
,
Al Ali
N
, et al
.
Risk prediction for clonal cytopenia: multicenter real-world evidence
.
Blood
.
2024
;
144
(
19
):
2033
-
2044
.
48.
Bernard
E
,
Tuechler
H
,
Greenberg
PL
, et al
.
Molecular international prognostic scoring system for myelodysplastic syndromes
.
NEJM Evid
.
2022
;
1
(
7
):
EVIDoa2200008
.
49.
Makishima
H
,
Saiki
R
,
Nannya
Y
, et al
.
Germ line DDX41 mutations define a unique subtype of myeloid neoplasms
.
Blood
.
2023
;
141
(
5
):
534
-
549
.
50.
Sebert
M
,
Passet
M
,
Raimbault
A
, et al
.
Germline DDX41 mutations define a significant entity within adult MDS/AML patients
.
Blood
.
2019
;
134
(
17
):
1441
-
1444
.
51.
Maierhofer
A
,
Mehta
N
,
Chisholm
RA
, et al
.
The clinical and genomic landscape of patients with DDX41 variants identified during diagnostic sequencing
.
Blood Adv
.
2023
;
7
(
23
):
7346
-
7357
.
52.
Homan
CC
,
Drazer
MW
,
Yu
K
, et al
.
Somatic mutational landscape of hereditary hematopoietic malignancies caused by germline variants in RUNX1, GATA2, and DDX41
.
Blood Adv
.
2023
;
7
(
20
):
6092
-
6107
.
53.
Li
M
,
Binder
M
,
Lasho
T
, et al
.
Clinical, molecular, and prognostic comparisons between CCUS and lower-risk MDS: a study of 187 molecularly annotated patients
.
Blood Adv
.
2021
;
5
(
8
):
2272
-
2278
.
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