Rare cytogenetic abnormalities in myelodysplastic syndromes

Association between Leukemic Evolution and Uncommon Chromosomal Alterations in Pediatric Myelodysplastic Syndrome

Background

Pediatric myelodysplastic syndrome (pMDS) is a group of rare clonal neoplasms with a difficult diagnosis and risk of progression to acute myeloid leukemia (AML). The early stratification in risk groups is essential to choose the treatment and indication for allogeneic hematopoietic stem cell transplantation (HSCT). According to the Revised International Prognostic Scoring System, cytogenetic analysis has demonstrated an essential role in diagnosis and prognosis. In pMDS, abnormal karyotypes are present in 30-50% of the cases. Monosomy 7 is the most common chromosomal alteration associated with poor prognosis. However, the rarity of specific cytogenetic alterations makes its prognosis uncertain. Thus, this study aimed to describe uncommon cytogenetic alterations in a cohort of 200 pMDS patients and their association with evolution to AML.

Methods

The cytogenetic analysis was performed in 200 pMDS patients by G-banding and fluorescence in situ hybridization between 2000 to 2022.

Results

Rare chromosome alterations were observed in 7.5% (15/200) of the cases. These chromosome alterations were divided into four cytogenetic groups: hyperdiploidy, biclonal chromosomal alterations, translocations, and uncommon deletions representing 33.3%, 33.3%, 20%, and 13.3%, respectively. Most of these patients (10/15) were classified with advanced MDS (MDS-EB and MDS/AML) and the initial subtype was present in five patients (RCC). The leukemic evolution was observed in 66.66% (10/15) of the patients. Most patients had poor clinical outcomes and they were indicated for HSCT.

Conclusion

The study of uncommon cytogenetic alterations in pMDS is important to improve the prognosis and guide early indication of HSCT.

Anaplastic Kaposi Sarcoma: A Clinicopathologic and Molecular Genetic Analysis

Kaposi sarcoma (KS) is a human herpesvirus 8 (HHV8)-associated vascular proliferation that most often involves the skin. Rarely, KS shows marked nuclear atypia or pleomorphism; such examples are known as "anaplastic" KS. This poorly characterized variant often pursues an aggressive course; little is known of its genetic landscape. This study evaluated the clinicopathologic and genomic features of anaplastic KS. We identified 9 anaplastic KS cases from 7 patients and 8 conventional KS cases, including a matched conventional KS and primary metastasis anaplastic KS pair from a single patient (anaplastic KS diagnosed 9 years after conventional KS). All patients with anaplastic KS were men, aged 51 to 82 years, who had locally aggressive tumors predominantly affecting the soft tissue and bone of the lower extremities (5/7 patients). Four patients were known to be HIV positive (all on antiretrovirals), 2 were HIV negative, and 1 was of unknown HIV status. The tumors showed angiosarcoma-like or pleomorphic spindle cell sarcoma morphology. Plasma cell-rich chronic inflammation and hemosiderin deposition were commonly present. Single-nucleotide polymorphism-based chromosomal microarray analysis showed the anaplastic KS cohort to demonstrate highly recurrent whole chromosome (chr) gains of chr 7, 11, 19, and 21, which primarily affected olfactory and G protein-coupled receptor signaling and losses of chr6_q and chrY. Compared with conventional KS, anaplastic KS cases showed significantly more total copy number alterations and more frequent gains of chr7 and chr11_q13.1 (MARK2, RELA, and ESRRA, including high copy number gain in 1 case). Pathway analysis demonstrated that these gains preferentially affected genes that facilitate cyclin-dependent cell signaling. Furthermore, anaplastic KS cases were phylogenetically distinct from conventional KS cases, including the patient-matched primary metastasis anaplastic KS pair and conventional KS. Our study is the first to demonstrate that a more complex genome and distinct copy number alterations distinguish anaplastic KS from conventional KS. Gains of chr7 and chr11_q13.1 appear central to biological transformation.

The Secondary Myelodysplastic Neoplasms (MDS) Jigsaw

There is a great deal of controversy in the hematologic community regarding the classification of secondary myelodysplastic neoplasms (MDSs). Current classifications are based on the presence of genetic predisposition and MDS post-cytotoxic therapy (MDS-pCT) etiologies. However, since these risk factors are not exclusive for secondary MDSs and there are multiple overlapping scenarios, a comprehensive and definitive classification is yet to come. In addition, a sporadic MDS might arise after a primary tumor fulfills the diagnostic criteria of MDS-pCT without a causative cytotoxicity. In this review, we describe the triggering pieces of a secondary MDS jigsaw: previous cytotoxic therapy, germline predisposition and clonal hematopoiesis. Epidemiological and translational efforts are needed to put these pieces together and ascertain the real weight of each of these pieces in each MDS patient. Future classifications must contribute to understanding the role of secondary MDS jigsaw pieces in different concomitant or independent clinical scenarios associated with the primary tumor.

Myelodysplastic syndrome in a 30-year-old man with coronavirus disease 2019 (COVID-19): a diagnostic challenge

Background

Myelodysplastic syndromes (MDS) mainly occur in the elderly but can rarely affect younger individuals too. The correct diagnosis relies on careful morphologic evaluation, cytogenetic/molecular results, and excluding reactive conditions mimicking MDS. We present the clinical, pathologic, cytogenetic, and molecular features of a case of MDS with excess blasts-2 (MDS-EB-2) in a 30-year-old male who was found to have pancytopenia during his hospitalization for coronavirus disease 2019 (COVID-19) and discuss the diagnostic challenges of MDS in patients with COVID-19.

Case presentation

A 30-year-old man presented to an outside hospital with fever, chills, weakness, coughing spells, dizziness and shortness of breath and was diagnosed with bilateral pneumonia due to COVID-19. At the outside hospital, he was found to be pancytopenic, and a subsequent bone marrow aspiration and biopsy raised concern for a COVID-19 induced hemophagocytic lymphohistiocytosis. In addition, MDS could not be ruled out. The patient was thus referred to our institute for further management. The patient’s peripheral blood showed pancytopenia with occasional dysplastic neutrophils and a few teardrop cells. Given the diagnostic uncertainty, a bone marrow aspiration and a biopsy were repeated revealing a hypercellular bone marrow with erythroid hyperplasia, megakaryocytic hyperplasia, trilineage dysplasia, increased blasts (13%), many ring sideroblasts, and mild to moderate myelofibrosis, consistent with MDS-EB-2. Chromosomal analysis revealed isochromosome 14. Next generation sequencing demonstrated SF3B1 K700E mutation.

Discussion and conclusion

The diagnosis of MDS can be challenging, particularly in young patients. Cytopenia and myelodysplastic features have been reported in COVID-19 patients, making the diagnosis of MDS more elusive. A careful pathologic examination of the bone marrow with ancillary studies including flow cytometry, immunohistochemistry, and cytogenetic and molecular studies in combination with a thorough clinical evaluation, leads to the accurate diagnosis.

Prognostic Markers of Myelodysplastic Syndromes

Myelodysplastic syndrome (MDS) is a clonal disease characterized by multilineage dysplasia, peripheral blood cytopenias, and a high risk of transformation to acute myeloid leukemia. In theory, from clonal hematopoiesis of indeterminate potential to hematologic malignancies, there is a complex interplay between genetic and epigenetic factors, including miRNA. In practice, karyotype analysis assigns patients to different prognostic groups, and mutations are often associated with a particular disease phenotype. Among myeloproliferative disorders, secondary MDS is a group of special entities with a typical spectrum of genetic mutations and cytogenetic rearrangements resembling those in de novo MDS. This overview analyzes the present prognostic systems of MDS and the most recent efforts in the search for genetic and epigenetic markers for the diagnosis and prognosis of MDS.

Prolonged response to recombinant human erythropoietin treatment in patients with myelodysplastic syndrome at a single referral centre in Brazil

OBJECTIVES

To evaluate the effects of epoetin (EPO) alfa treatment on overall survival, event-free survival and response duration in patients with myelodysplastic syndrome (MDS) who were treated at a haematological referral centre in northeastern Brazil.

METHODS

This was a retrospective cohort study of 36 patients diagnosed with MDS and treated with EPO alfa at 30,000 to 60,000 IU per week. Clinical data were collected from medical records. The events assessed were non-response to treatment and progression to acute myeloid leukaemia (AML). Statistical analyses were performed using GraphPad Prism 7 and SPSS 24 software.

RESULTS

The overall survival of patients who received EPO alfa treatment was 51.64%, with a median of 65 months of treatment, and the overall survival of this group was 100% during the first 24 months. We detected a 43.5-month median event-free survival, with a response rate of 80.5%. We observed responses from 25 to 175 months. Patients with transfusion dependence and those with a high-risk stratification, as determined by the International Prognostic Scoring System (IPSS), the Revised International Prognostic Scoring System (IPSS-R), the WHO classification-based Prognostic Scoring System (WPSS) and the WHO 2016, had a lower event-free survival than other patients.

CONCLUSIONS

Despite the wide use of EPO alfa in the treatment of anaemia in patients with MDS, the median response duration is approximately only 24 months. Our data provide encouraging results concerning the benefits of using EPO alfa for the improvement of the quality of life, as patients treated with EPO showed higher overall survival, event-free survival rates and longer response durations than have been previously described in the literature.

A Case of Acquired Haemophilia A in a Patient with Chronic Myelomonocytic Leukaemia

A 67-year-old male, with a known diagnosis of myelodysplastic syndromes with multilineage dysplasia (MDS-MLD) was admitted to our hospital with a primary complaint of subcutaneous bleeding in his left thigh. Laboratory data showed anaemia and prolongation of activated partial thromboplastin time (85.8 s, normal range 24-39 s) without thrombocytopenia. Coagulation factor VIII (FVIII) activity was less than 1% (normal range 60-150%), and a FVIII inhibitor was identified and quantified at 166 BU/mL to indicate a diagnosis of acquired haemophilia A (AHA). A recent, but sustained circulating monocytosis (>1 × 10⁹/L) was observed, which combined with elevated numbers of neutrophil and monocytic cells in the marrow, suggested evolution of MDS-MLD to chronic myelomonocytic leukaemia (CMML), coinciding with AHA. Further analysis revealed a karyotype of 46, XY, i(14) (q10), which was the same abnormality previously identified in the patient. To treat bleeding caused by AHA, steroid and activated prothrombin complex concentrate were administered. Azacitidine (AZA) was used to treat CMML. During the clinical course, bleeding partially improved; however, subsequent acute myocardial infarction occurred on day 87. Worsening bone marrow failure was observed 4 months after the original admission, despite administration of AZA therapy, and the patient died due to bleeding from AHA. This case suggests that the evolution of MDS to CMML status can be associated with AHA conferring a bleeding tendency.

Severe Eosinophilia in Myelodysplastic Syndrome With a Defined and Rare Cytogenetic Abnormality

Myelodysplastic syndromes (MDS) are a heterogeneous group clonal disorders of hematopoietic stem cells (HSC) characterized by ineffective hematopoiesis that lead to variable grades of impaired blood cell production. Chromosomal aberrations are often detected in MDS patients and thus cytogenetic analysis is useful for the diagnosis of these disorders. Common recurring chromosomal defects, such as the −5/5q- and −7/7q- are relatively well characterized cytogenetic abnormalities in MDS, however, the biological significance of uncommon cytogenetic alterations is unknown. We report here, two cases of peripheral blood and bone marrow hypereosinophilia in patients with MDS harboring the unbalanced translocation der(1;7)(q10;p10), a poorly characterized cytogenetic abnormality that is found in certain myeloid malignancies, including MDS. The patients reported here presented hypereosinophilia that was refractory to steroids and cytotoxic therapy, leading to severe target tissue damage that ultimately resulted in fatal end-organ failure. Potential roles of the der(1;7)(q10;p10) aberrations in the pathogenesis of aggressive eosinophilia and disease prognosis are discussed here.

From cellular morphology to molecular and epigenetic anomalies of myelodysplastic syndromes

Myelodysplastic syndromes (MDSs) are a myeloid neoplasm with a propensity for natural evolution or transformation to acute leukemias (AL) over time. Mechanisms for MDS transformation to AL remain poorly understood but are related to genomic instability, which affects the production of the different cell lineages. Genomic instability is also generated by dysfunctional telomeres. Indeed telomeres, the protective ends of chromosomes are the backbone of genome stability. Nuclear telomere remodeling is an early indicator of nuclear remodeling preceding the onset of genomic instability and MDS. This review aims to revisit the pathogenesis and pathophysiology of MDS from morphology and cytogenetics to molecular and epigenetic mechanisms. Furthermore, this review will highlight and discuss recent breakthroughs in dysfunctional telomeres and nuclear telomere architecture roles in the pathogenesis and physiopathology of MDS in the global context of genomic instability.

"Reversible" myelodysplastic syndrome or ineffectual clonal haematopoiesis? - add(6p) myeloid neoplasm with a spontaneous cytogenetic remission

Cytotoxic chemotherapy has inherent mutagenic potential and alters the bone marrow microenvironment after therapy. In some cases, this potentiates expansion of an aberrant clone and may lead to a therapy-related myeloid neoplasm if the clone overcomes selective pressure. We present the case of a 43-year-old woman diagnosed with an indolent, therapy-related myeloid neoplasm with an isolated chromosome 6p abnormality following treatment for de novo Acute Myeloid Leukaemia (AML), who manifest a sustained spontaneous cytogenetic remission two years later, possibly due to an ineffectual or non-dominant founding clone. This case reminds us to be mindful of the possibility that clonal haematopoiesis may not always equate to clinically relevant disease, even in the setting of an abnormal clonal karyotype.

Diagnostic algorithm for lower-risk myelodysplastic syndromes

Rapid advances over the past decade have uncovered the heterogeneous genomic and immunologic landscape of myelodysplastic syndromes (MDS). This has led to notable improvements in the accuracy and timing of diagnosis and prognostication of MDS, as well as the identification of possible novel targets for therapeutic intervention. For the practicing clinician, however, this increase in genomic, epigenomic, and immunologic knowledge needs consideration in a "real-world" context to aid diagnostic specificity. Although the 2016 revision to the World Health Organization classification for MDS is comprehensive and timely, certain limitations still exist for day-to-day clinical practice. In this review, we describe an up-to-date diagnostic approach to patients with suspected lower-risk MDS, including hypoplastic MDS, and demonstrate the requirement for an "integrated" diagnostic approach. Moreover, in the era of rapid access to massive parallel sequencing platforms for mutational screening, we suggest which patients should undergo such analyses, when such screening should be performed, and how those data should be interpreted. This is particularly relevant given the recent findings describing age-related clonal hematopoiesis.

Cytogenetic Abnormalities in Myelodysplastic Syndromes: An Overview

Karyotype is one of the main constituents of the International Prognostic Scoring System (IPSS) and revised-IPSS that are the cornerstones for the prognostication of patients with myelodysplastic syndromes (MDS). Del(5q), -7/del(7q), +8 and -Y are among the most extensively studied cytogenetic abnormalities in MDS. The same applies for normal karyotype. There are hundreds of other rare cytogenetic abnormalities that have been reported in MDS, included but not limited to -X, 3q abnormalities, +13/del(13q), i(17q), +21/-21. However, due to a very low number of patients, their impact on the prognosis of MDS is limited. Knowledge of the molecular consequences of different cytogenetic abnormalities allows us to modify treatment regimens based on drugs most active against the specific karyotype present, allowing for the opportunity to individualize MDS treatment and improve patient care and prognosis.