Guide to the Diagnosis of Myeloid Neoplasms: A Bone Marrow Pathology Group Approach

OBJECTIVES

The practicing pathologist is challenged by the ever-increasing diagnostic complexity of myeloid neoplasms. This guide is intended to provide a general roadmap from initial case detection, often triggered by complete blood count results with subsequent blood smear review, to final diagnosis.

METHODS

The integration of hematologic, morphologic, immunophenotypic, and genetic features into routine practice is standard of care. The requirement for molecular genetic testing has increased along with the complexity of test types, the utility of different testing modalities in identifying key gene mutations, and the sensitivity and turnaround time for various assays.

RESULTS

Classification systems for myeloid neoplasms have evolved to achieve the goal of providing a pathology diagnosis that enhances patient care, outcome prediction, and treatment options for individual patients and is formulated, endorsed, and adopted by hematologists/oncologists.

CONCLUSIONS

This guide provides diagnostic strategies for all myeloid neoplasm subtypes. Special considerations are provided for each category of testing and neoplasm category, along with classification information, genetic testing requirements, interpretation information, and case reporting recommendations based on the experience of 11 Bone Marrow Pathology Group members.

Co-existing squamous cell carcinoma and chronic myelomonocytic leukemia with ASXL1 and EZH2 gene mutations: A case report

BACKGROUND

Chronic myelomonocytic leukemia (CMML), a rare clonal hematopoietic stem cell disorder characterized by myelodysplastic syndrome and myeloproliferative neoplasms, has a generally poor prognosis, and easily progresses to acute myeloid leukemia. The simultaneous incidence of hematologic malignancies and solid tumors is extremely low, and CMML coinciding with lung malignancies is even rarer. Here, we report a case of CMML, with ASXL1 and EZH2 gene mutations, combined with non-small cell lung cancer (lung squamous cell carcinoma).

CASE SUMMARY

A 63-year-old male, suffering from toothache accompanied by coughing, sputum, and bloody sputum for three months, was given a blood test after experiencing continuous bleeding resulting from a tooth extraction at a local hospital. Based on morphological results, the patient was diagnosed with CMML and bronchoscopy was performed in situ to confirm the diagnosis of squamous cell carcinoma in the lower lobe of the lung. After receiving azacitidine, programmed cell death protein 1, and platinum-based chemotherapy drugs, the patient developed severe myelosuppression and eventually fatal leukocyte stasis and dyspnea.

CONCLUSION

During the treatment and observation of CMML and be vigilant of the growth of multiple primary malignant tumors.

Laboratory Evaluation and Pathological Workup of Neoplastic Monocytosis - Chronic Myelomonocytic Leukemia and Beyond

PURPOSE OF REVIEW

Monocytosis is a distinct but non-specific manifestation of various physiologic and pathologic conditions. Among hematopoietic stem cell neoplasms, depending on the criteria used for disease classification, monocytosis may be a consistent and integral component of diseases such as chronic myelomonocytic leukemia or acute myeloid leukemia with monocytic differentiation, or it may represent an inconsistent finding that often provides a clue to the underlying genetic changes driving the neoplasm. The purpose of this review is to provide the readers with a laboratory-based approach to neoplastic monocytosis.

RECENT FINDINGS

In-depth elucidation of the genomic landscape of myeloid neoplasms within the past few years has broadened our understanding of monocytosis and its implications for diagnosis and prognosis. Genetic findings also shed light on potential disease response - or lack thereof - to various therapeutic agents used in the setting of myeloid neoplasms. In this review, we provide our approach to diagnose neoplastic monocytosis in the context of case-based studies while incorporating the most recent literature on this topic.

Traipsing Through Muddy Waters: A Critical Review of the Myelodysplastic Syndrome/Myeloproliferative Neoplasm (MDS/MPN) Overlap Syndromes

Myelodysplastic syndrome/Myeloproliferative neoplasms (MDS/MPNs) are molecularly complex, clinically heterogeneous diseases that exhibit proliferative and dysplastic features. Diagnostic criteria use clinical, pathologic, and genomic features to distinguish between disease entities, though considerable clinical and genetic overlap persists. MDS/MPNs are associated with a poor prognosis, save for MDS/MPN with ring sideroblasts and thrombocytosis, which can behave more indolently. The current treatment approach is risk-adapted and symptom-directed and largely extrapolated from experience in MDS or MPN. Gene sequencing has demonstrated frequent mutations involving signaling, epigenetic, and splicing pathways, which present numerous therapeutic opportunities for clinical investigation.

The relationship between red cell distribution width and prognostic scores in myelodysplastic syndrome

Introduction

The myelodysplastic syndrome (MDS) represents a group of hematopoietic neoplasms that is characterized by clonal hematopoiesis, cytopenia and abnormal cellular maturation. Red cell distribution width (RDW) refers to the variation degree of erythrocyte size and it is a reflection of anisocytosis. Higher values have been linked to adverse outcomes, such as increased mortality, vascular events, kidney and liver disease and demonstrated to harbor poor prognosis in solid and hematological malignancies. The RDW value can be used as a contributing parameter for MDS diagnosis, as well as its prognosis. In this study, we essentially aimed to demonstrate the correlation between the RDW and MDS prognostic indexes.

Materials and methods

Ninety-four MDS patients at the Aydın Adnan Menderes University Hematology Division were included in the study. The correlations between the RDW and laboratory values (either lactate dehydrogenase, albumin, globulin or ferritin) and the RDW prognostic scoring indexes (IPSS, WPSS, IPSS-R and LR-PSS) were investigated. The PASW for Windows, version 21.0 (SPSS Inc., Chicago, IL, USA), was used for statistical assessment. A p-value below 0.05 was the cut-off for the statistical significance.

Results

The mean age of all the patients was 73 ± 10 years. Patients were observed for 41.88 ± 25 months. The mean RDW value for all cases was 15.5 ± 2.39. We found a statistically significant difference of survival between RDW values below and above 15.5% (p = 0.016). A significant difference was also observed according to the prognostic scoring indexes (see below).

Conclusion

An increase in RDW is probably related to dysplasia in the MDS and this constitutes a possible explanation for the poor outcome. Prognostic indexes might incorporate the RDW as a parameter in the future.

Convalescent (immune) plasma treatment in a myelodysplastic COVID-19 patient with disseminated tuberculosis

During the ongoing COVID-19 pandemic due to the SARS-CoV-2 virus of which evidence-based medical paradigms cannot be easily applied; difficult clinical decisions shall be required particularly in the 'difficult-to-treat' cases of high risk group with associated comorbidities. Convalescent immune plasma therapy is a promising option as a sort of 'rescue' treatment in COVID-19 immune syndrome, where miraculous antiviral drugs are not available yet. In this report, we aim to convey our experience of multi-task treatment approach with convalescent immune plasma and anti-cytokine drug combination in a COVID-19 patient with extremely challenging comorbidities including active myeloid malignancy, disseminated tuberculosis and kidney failure.

Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U): More than just a "catch-all" term?

The clinicopathology of MDS and MPN are not mutually exclusive and for this reason the category of myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) exists. Several sub-entities have been included under the MDS/MPN umbrella, including MDS/MPN-unclassifiable (MDS/MPN-U) for those cases whose morphologic and clinical phenotype do not meet criteria to be classified as any other MDS/MPN sub-entity. Though potentially regarded as a wastebasket diagnosis, since its integration into myeloid disease classification, MDS/MPN-U has been refined with increasing understanding of the mutational and genomic events that drive particular clinicopathologic phenotypes, even within MDS/MPN-U. The prototypical example is the identification of SF3B1 mutations and its durable association with MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T), an entity previously buried within, but now a separate category outside of MDS/MPN-U. Continued and enhanced study of those entities under MDS/MPN-U, a perhaps provisional category itself, is likely to progressively identify commonality between many "unclassifiables" to establish a new classifiable diagnosis.

Systematic review of azacitidine regimens in myelodysplastic syndrome and acute myeloid leukemia

Background

5-Azacitidine administered as a 7-day dosing regimen (7–0-0) is approved in high risk IPSS myelodysplastic syndrome (MDS) patients. Alternative regimens such as a 5-day (5–0-0) or 7-day with a weekend break (5–2-2) are commonly used. No randomized controlled trial has been done directly comparing all three dosing regimens. The objective of this study was to compare the efficacies of the 5–0-0, 5–2-2, and 7–0-0 regimens in MDS and AML.

Methods

A systematic review was conducted using MEDLINE, EMBASE and CENTRAL. Eligible studies were randomized controlled trials (RCTs), observational prospective and retrospective studies. The primary clinical outcomes were Objective Response Rate (ORR) defined as the sum of complete response (CR), partial response (PR), and hematological improvement (HI) as defined by the IWG 2006 criteria. A meta-analysis of simple proportions was conducted using a random effects model with weights defined according to Laird and Mosteller. Comparisons between groups were not attempted due to the heterogeneity of study designs.

Results

The only RCT directly comparing alternative azacitidine regimens showed no difference in ORR between the 5–0-0 and 5–2-2 regimens. All other RCTs compared a dosing regimen to conventional care. The pooled proportion of ORR was 44.8% with 95% CI (42.8%, 45.5%) for 7–0-0, 41.2% with 95% CI (39.2%, 41.9%) for 5–0-0, and 45.8% with 95% CI (42.6%, 46.4%) for 5–2-2.

Conclusions

Indirect comparison of alternative azacitidine dosing regimens in MDS and AML shows a benefit for the 7-day regimen in attaining ORR. Additional RCTs are required to definitively address this comparison.

Electronic supplementary material

The online version of this article (10.1186/s12878-017-0094-8) contains supplementary material, which is available to authorized users.

CMML: Clinical and molecular aspects

Chronic Myelomonocytic Leukemia is a chronic myeloid neoplasm occurring mostly in the elderly with overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN) characterized by chronic monocytosis. Recent progresses in the molecular and cellular pathogenesis of CMML have stirred a renewed interest in this clinically heterogeneous disorder. Here, we review the recent progresses in the biology of CMML and how it affects its current and future clinical management.

Survey of experts on therapeutic policies and proposals for the optimal timing for allogeneic peripheral blood stem cell transplantation in transfusion-dependent patients with myelodysplastic syndrome-refractory anemia

BACKGROUND

Most hypomethylating agent (HMA) responders with myelodysplastic syndrome (MDS) eventually need allogeneic stem cell transplantation (SCT) because they often acquire resistance to HMAs within two years of treatment. Considering the nature of MDS and the poor outcomes of SCT when performed after confirming the progression of MDS to acute myeloid leukemia (AML), allogeneic SCT should be performed with caution in patients with low-risk MDS.

METHODS

To address low-risk MDS, the Korean AML/MDS working party group designed a survey for 34 MDS experts in Korea on therapeutic HMA and allogeneic SCT policies for low-risk MDS. The level of consensus was defined as the percentage of agreement among the experts.

RESULTS

With regard to the optimal time for allogeneic SCT for HMA responders with MDS-RA, 76% experts agreed that allogeneic SCT should be performed when a patient has a low platelet count. With regard to the relapse pattern that was most commonly found during HMA treatment in responding patients with MDS-RA, 54% experts agreed that the most common pattern that indicated HMA failure was the gradual worsening of cytopenia.

CONCLUSION

The optimal time to perform allogeneic SCT in RA patients who achieved hematologic complete remission during HMA treatment is when the platelet count decreases. However, these suggestions need to be evaluated in larger future studies. Therefore, careful decisions should be taken at each step of allogeneic SCT to maximize the outcomes for patients with MDS-RA and iron overload.

Transformation of the 5q- syndrome to acute lymphoblastic leukemia: a report of two cases and review of the literature

Myelodysplastic syndrome (MDS) with an isolated deletion of the long arm of chromosome 5 (5q- syndrome) is a distinct subtype of MDS with an indolent course that rarely transforms to acute leukemia. Deletion of the long arm of chromosome 5 has also been reported in rare cases of de novo B-lymphoblastic leukemia. We present two cases of 5q- syndrome with a similar and unusual course of transformation to lymphoblastic leukemia while on Lenalidomide. These two patients achieved an initial response; however, later acquired a second cytogenetic abnormality, became refractory to treatment and evolved into acute leukemia. At the time of transformation, both patients had recurrence of the 5q- abnormality. Review of the literature and the mechanisms of transformation of the 5q-syndrome into an acute leukemia are discussed. Although the relationship between the events in our cases remains unclear, the intriguing similarity between the two cases raises a question whether immune modulators can alter the natural course of MDS. To our knowledge, no similar cases were previously reported in the literature.