Allogeneic hematopoietic stem cell transplantation for isolated and leukemic myeloid sarcoma in adults: a report from the Acute Leukemia Working Party of the European group for Blood and Marrow Transplantation

A Rare Case of Partial Small Bowel Obstruction Secondary to Intestinal Myeloid Sarcoma

This case report details a rare case of small bowel myeloid sarcoma (MS) in an otherwise fit and well 49-year-old male presenting initially with vague obstructive symptoms and weight loss. The patient ultimately required an operation for a small bowel obstruction where a laparotomy and small bowel resection were performed due to three cicatrising completely obstructing lesions in the mid-jejunum. Fewer than 1% of patients with acute myeloid leukaemia (AML) present with MS as an initial diagnosis, and only 6.5% of these are intestinal in origin. This report adds to the current body of literature on this rare condition, emphasises the diagnostic challenges resulting in delays to diagnosis, and discusses the crucial role of early and accurate identification for optimal treatment and prognosis. Surgery may be warranted in patients with complications such as obstruction; however, systemic chemotherapy tailored to AML is the primary therapeutic approach for MS patients.

Myeloid sarcoma: An overview

Myeloid Sarcoma (MS) is a high grade, hematological malignancy defined as an extramedullary tumor mass of myeloid blasts with or without maturation that effaces tissue architecture. It is a highly heterogenous condition that represents a variety of myeloid neoplasms. This heterogeneity of MS, together with its rarity, have greatly hampered our understanding of the condition. Diagnosis requires tumor biopsy, which should be accompanied by bone marrow evaluation for medullary disease. It is presently recommended that MS be treated similar to AML. Additionally, ablative radiotherapy and novel targeted therapies may also be beneficial. Genetic profiling has identified recurrent genetic abnormalities including gene mutations associated with MS, supporting its etiology similar to AML. However, the mechanisms by which MS homes to specific organs is unclear. This review provides an overview of pathogenesis, pathological and genetic findings, treatment, and prognosis. Improving the management and outcomes of MS patients requires a better understanding of its pathogenesis and its response to various therapeutic approaches.

Extramedullary Myeloid Leukemia in the Setting of a Myeloproliferative Neoplasm

Extramedullary acute myeloid leukemia (EML), also known as myeloid sarcoma (MS), is an extramedullary solid mass derived from the proliferation of myeloblasts outside of the bone marrow. EML can present independently or concurrently with intramedullary acute myeloid leukemia (iAML). It can happen de novo or secondary to iAML, myeloproliferative neoplasm (MPN), chronic myelomonocytic leukemia (CMML), or myelodysplastic syndrome (MDS). We present a 57-year-old female with a history of Janus kinase 2 (JAK-2)-positive essential thrombocythemia (ET) evolving into EML in the setting of a persistent TP53 mutation. We discuss the essential diagnostic studies including tissue biopsy and fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) imaging. We also investigate the significance of cytogenetics and next-generation sequencing (NGS) along with the unique pathogenesis, treatment and prognostic implications.

Clinical Characteristics and Treatment Outcomes of Myeloid Sarcoma in Children: The Experience of the Polish Pediatric Leukemia and Lymphoma Study Group

Introduction

Myeloid sarcoma (MS) is an extramedullary malignant tumor composed of immature myeloid cells. It occurs in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or chronic myeloid leukemia (CML). MS may coincide with disease diagnosis or precede bone marrow involvement by months or even years; it can also represent the extramedullary manifestation of a relapse (1, 2).

Aim

The aim of this study is to describe clinical characteristics of children diagnosed with MS in Poland as well as to analyze diagnostic methods, treatment, and outcomes including overall survival (OS), relapse-free survival (RFS), and event-free survival (EFS). The study also attempted to identify factors determining treatment outcomes.

Patients

The study group comprised 43 patients (F=18, M=25) aged 0-18 years (median age, 10.0 years; mean age, 8.8 years) diagnosed with MS based on tumor biopsy and immunohistochemistry or identification of underlying bone marrow disease and extramedullary tumor according to imaging findings.

Methods

The clinical data and diagnostic and therapeutic methods used in the study group were analyzed. A statistical analysis of the treatment outcomes was conducted with STATISTICA v. 13 (StatSoft, Inc., Tulsa, OK, USA) and analysis of survival curves was conducted with MedCalc 11.5.1 (MedCalc Software, Ostend, Belgium). Statistical significance was considered at p<0.05.

Results

In the study group, MS was most frequently accompanied by AML. The most common site of involvement was skin, followed by orbital region. Skin manifestation of MS was more common in the age group <10 years. The most frequent genetic abnormality was the t(8;21)(q22;q22) translocation. The 5-year OS probability (pOS), 5-year RFS probability (pRFS), and 5-year EFS probability (pEFS) were 0.67 ± 0.08, 0.79 ± 0.07, and 0.65 ± 0.08, respectively. In patients with isolated MS and those with concurrent bone marrow involvement by AML/MDS, pOS values were 0.56 ± 0.12 and 0.84 ± 0.09 (p=0.0251), respectively, and pEFS values were 0.56 ± 0.12 and 0.82 ± 0.08 (p=0.0247), respectively. In patients with and without the t(8;21)(q22;q22) translocation, pEFS values were 0.90 ± 0.09 and 0.51 ± 0.14 (p=0.0490), respectively.

Conclusions

MS is a disease with a highly variable clinical course. Worse treatment outcomes were observed in patients with isolated MS compared to those with concurrent bone marrow involvement by AML/MDS. Patients with the t(8;21)(q22;q22) translocation were found to have significantly higher pEFS. MS location, age group, chemotherapy regimen, surgery, and/or radiotherapy did not have a significant influence on treatment outcomes. Further exploration of prognostic factors in children with MS is indicated.

Microtransplantation for myeloid sarcoma: Two case reports

Myeloid sarcoma (MS), is a rare extramedullary tumor with a poor prognosis and high recurrence rate. Microtransplantation is one of the alternative methods of traditional transplantation, which does not rely on HLA complete matching, has low toxicity and may retain part of graft-versus-leukemia (GVL) effect. It has been reported that microtransplantation can significantly improve the survival rate of elderly AML patients. At present, there is no report on the application of micro transplantation in MS. We will report two cases of MS treated by micro transplantation. The disease-free survival was 66 months and 55 months respectively.

Extramedullary acute myeloid leukemia (eAML): Retrospective single center cohort study on clinico-pathological, molecular analysis and survival outcomes

Introduction

extramedullary acute myeloid leukemia (eAML) is characterized by extramedullary tumor formation infiltrated by myeloid blasts, with or without maturation and effaced architecture. The clinical, genetic and molecular aspects and overall outcomes are well defined worldwide, but not well characterized in our region.

Purpose and methods

This is a retrospective single center cohort study on 32 patients, who were identified over 10 years to study the clinical, pathologic and genetic-molecular aspects, and survival outcomes.

Results

eAML is rare (1%), occurs at a younger age with male predominance. Central nervous system (CNS) with facial bone invasion is most commonly identified (34.4%). 45.5% were positive for conventional myeloid markers (MPO), CD33, CD117, and 36% positive for CD34 and CD68. 54% with normal karyotype had deleterious mutations on further testing. NGS revealed pathogenic mutations in 76%(N-9/17) and none tested positive for P53, IDH1 or IDH2. At a median follow up time of 43mo (range, 8.6–80mo); 37.5%(N-12) were in complete remission, 62.5%(N-20) relapsed. 28% of relapses were after allotransplant. 31%(N-10) alive and continued in complete remission(CR), and 69%(N-22) of patients have died.

Median overall survival (OS) is 18.4 and relapse free survival (RFS) 18.7 months. OS and RFS were significantly better in patients, who attained CR after induction (IC 11.9 mo vs zero; P = 0.0001; IC 12mo vs zero; P = 0.0001) compared to patients with relapsed disease; and in patients who received allo-transplant consolidation with median OS and RFS 42 vs 8.5mo (P = 0.002) and 42months vs 10 mo (P = 0.006). Thus allotransplant may be considered for all eligible patients in first CR.

Conclusion

achievement of complete remission after induction therapy is associated with improved outcomes in eAML. Allotransplant in first complete remission may be the most effective modality for achieving long-term remissions.

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eAML is a rare entity and occurs at a younger in Jordan.

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It requires advanced methods for the diagnosis, and identification of targetable mutations, that may dictate therapeutic approaches.

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AML-like induction chemotherapy regimens remain the standard of care, and consolidation therapy is controversial.

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Failure to achieve complete remission is associated with worse survival outcomes.

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Allogeneic hematopoietic transplant may be considered in first complete remission.

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Post-transplant relapses are common and responsible for increased mortality and shorter survival.

Gastrointestinal Myeloid Sarcoma a Case Presentation and Review of the Literature

Myeloid sarcomas can be detected in up to 30% of acute myeloid leukemia cases or occur de-novo without bone marrow involvement. The most frequent localization of myeloid sarcomas in the abdominal cavity is the small intestine, and gastric presentations are infrequent, frequently misdiagnosed, and a high level of suspicion should exist when the characteristic histomorphology features are present. The current review features a case report with gastric presentation of myeloid sarcoma in a patient with a diagnosis of acute myeloid leukemia with trisomy 8. In addition, a review of the literature of intestinal-type myeloid sarcomas shows that less than 15% of these cases have been reported in the stomach. The most common molecular aberrancy detected in intestinal myeloid sarcomas is the fusion protein CBFB-MYH11. A review of several large studies demonstrates that the presence of myeloid sarcoma does not constitute an independent prognostic factor. The therapeutic approach will be tailored to the specific genetic abnormalities present, and systemic chemotherapy with hematopoietic stem cell transplant is the most efficient strategy.

A case of primary nonleukemic myeloid sarcoma of the spleen, successfully treated by surgery and hematopoietic stem cell transplantation

Background

Myeloid sarcoma (MS) is a rare disease, mostly found in conjunction with acute myelogenous leukemia or other diseases, and primary nonleukemic MS of the spleen is particularly rare.

Case presentation

We report a 57-year-old male who presented with a spleen mass that was found incidentally, and was enlarged. As a result of various examinations, he was diagnosed with primary MS of the spleen with suspected involvement of the transverse colon, left kidney, pancreatic tail, and left diaphragm. He underwent a total splenectomy, partial pancreatectomy, partial colectomy, left nephrectomy, and left diaphragm partial resection. Histological examination revealed splenic primary MS. Bone marrow biopsy and immunophenotypic flow cytometry revealed no evidence of myeloid leukemia. He underwent umbilical cord blood transplantation, and he is currently living without a sign of recurrence at 10 months after surgery.

Conclusions

We experienced a very rare case of primary spleen MS that was discovered without a hematologic malignancy. Two cases of surgically resected primary splenic MS have been reported, including the present case.

De novo isolated myeloid sarcoma: comparative analysis of survival in 19 consecutive cases

Institutional database search (1999-2020) for acute myeloid leukaemia (AML) identified 109 cases of myeloid sarcoma (MS), of which 19 were isolated and presented de novo. The latter displayed longer survival (median 78 months), compared to MS with synchronous intramedullary AML (n = 32; median 16 months) and de novo AML without MS (n = 729; median 22 months; P = 0·13). However, the difference in survival was no longer apparent after accounting for bone marrow cytogenetic risk status (P = 0·67). Treatment-induced MS tumour resolution was not affected by the presence of intramedullary disease (P = 0·61). The current study clarifies the prognosis of de novo isolated MS, in the context of AML.

The myeloid sarcoma treated by Venetoclax with hypomethylating agent followed by stem cell transplantation: rare case report

BACKGROUND

Myeloid sarcoma (MS) is a very rare condition, develops both in patients with other hematological neoplasms, and as isolated tumor. MS of the gynecologic tract is extremely rare. An available literature data about diagnosis and management of MS is summarized in the article. The role of chemotherapy, radiation therapy, surgery and bone marrow transplantation in the treatment is discussed. Polychemotherapy and allogeneic bone marrow transplantation were suggested to be the optimal treatment strategy of MS of the gynecological tract. The use of new targeted agents results in promising clinical data.

CASE PRESENTATION

We are presenting a rare clinical case of a MS of the uterine cervix with concomitant bone marrow involvement and describe all the peculiarities of the clinical course, diagnosis, and treatment. The patient received chemotherapy followed by allogeneic bone marrow transplantation. The pre-transplant therapy allowed us to perform allogeneic bone marrow transplantation with the deepest response possible: complete PET-negative and MRD-negative remission of the disease.

CONCLUSIONS

MS remains a subject of discussion regarding its diagnostic and therapeutic aspects. The use of novel targeting agents can be perspective option for patient with extramedullary disease.

Primary peritoneal myeloid sarcoma in association with CBFB/MYH11 fusion

Myeloid sarcoma, also known as chloroma or granulocytic sarcoma is an extramedullary disease process that typically presents in association with acute myeloid leukemia during initial presentation or at relapse. Often associated with cytogenetic mutations, including t(8;21)(q22;q22); RUNX1/RUNX1T1, and less frequently with inv(16)(p13.1q22) or t(16;16)(p13.1;q22); CBFB/MYH11, myeloid sarcoma is most commonly discovered in skin, soft tissue, bone, and connective tissue. In rare circumstances, myeloid sarcoma can present without any evidence of bone marrow or leukemic involvement. These cases of de novo myeloid sarcoma are rare, and are commonly misdiagnosed due to similarities with other entities. We report an unusual case of a primary de novo peritoneal myeloid sarcoma, in association with inv(16)(p13;q22) and clonal heterogeneity at different sites of involvement, that has responded well to AML induction therapy and consolidation treatment with gemtuzumab ozogamicin and high dose cytarabine. Cytogenetics, immunophenotyping, and chromosomal analysis, were each critical in establishing a proper diagnosis as well as helping to develop appropriate therapeutic strategies for this rare entity.

Characteristics and prognosis of pediatric myeloid sarcoma in the cytogenetic context of t(8;21)

The prognosis of myeloid sarcoma (MS) is controversial. Many reports indicated that orbital-MS has a good prognosis and is closely related to t(8;21), but the prognostic role of MS in pediatric t(8;21) AML is unclear. We retrospectively analyzed data from 127 patients with pediatric t(8;21) AML diagnosed between January 2010 and June 2018. We compared patients with (n = 30) and without MS (n = 97). The median follow-up time was 52.6 months. The proportion of t(8;21) AML patients with MS was 23.6%. Males were more likely to have MS than females. The complete remission rate after the first course of induction chemotherapy and the 3-year relapse-free survival (RFS) among patients with MS were lower than those among patients without MS (60% vs. 78.4%, p = 0.045) (68.8 ± 8.8% vs. 88.0 ± 3.4%, p = 0.004). The female sex and a higher level of RUNX1/RUNX1T1 transcripts after consolidation were risk factors for poor RFS among patients with MS. Our data showed that MS was an independent risk factor in pediatric t(8;21) AML. Close monitoring of measurable residual disease of the bone marrow and extramedullary lesions is needed to guide stratified treatment.

Characteristics and transplant outcome of myeloid sarcoma: a single-institute study

We performed a retrospective study describing the characteristics of myeloid sarcoma (MS) and evaluated the outcome of hematopoietic stem cell transplantation (HSCT) in patients with MS. There were 27 patients with de novo isolated MS, 34 with de novo leukemic MS and 13 with secondary leukemic MS in our study. Sixty-three patients received induction chemotherapy. Following induction therapy, 35 patients underwent HSCT, including 10 autogenous HSCT (auto-HSCT) and 25 allogeneic HSCT (allo-HSCT) cases. Compared with intensive chemotherapy only as consolidation treatment, HSCT (auto-/allo-HSCT) significantly improved the overall survival (OS) of MS patients (p < 0.05), while allo-HSCT also improved progression-free survival (PFS, p = 0.032). According to multivariate analysis, poorer prognosis in terms of OS was observed in older patients (p = 0.024, HR = 1.030, 95% CI 1.004-1.057), while HSCT (auto/allo-HSCT) had a favorable impact on OS for patients with MS (auto-HSCT, p = 0.044, HR = 0.201, 95% CI 0.042-0.959; allo-HSCT, p = 0.038, HR = 0.341, 95% CI 0.124-0.943). Extramedullary disease without complete remission (CR) after induction therapy was the sole variable independent of high OS and PFS (p = 0.049, HR = 2.243, 95% CI: 1.005-5.005; p = 0.017, HR = 2.535, 95% CI 1.180-5.448, respectively). The data indicate that HSCT is an effective treatment for patients with MS who have achieved CR of extramedullary disease after induction therapy.

Haploidentical hematopoietic stem cell transplantation for patients with myeloid sarcoma: a single center retrospective study

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been regarded as a potential strategy for myeloid sarcoma (MS). The previous reports focused mainly on matched sibling donor (MSD) or matched unrelated donor (MUD) transplantation. There are no reports on haploidentical HSCT (haplo-HSCT) in MS. We retrospectively reviewed 14 MS patients who underwent haplo-HSCT. All patients achieved complete donor engraftment. The median time for neutrophil engraftment and platelet engraftment were 10 (12-21) days and 18 (8-31) days. The 100-day cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) and 3-year cumulative incidence of chronic GVHD were 37.7% (95%CI, 23.2-52.1%) and 35.7% (95%CI, 22.2-49.2%). Cytomegalovirus (CMV) reactivation was documented in 86% patients, and only one patient developed CMV pneumonia. Treatment-related mortality occurred in one (7%) patient. The 1- and 3-year cumulative incidence of relapse was 21.4% (95%CI, 11.8-31.1%) and 35.7% (95%CI, 22.4-49.0%). The probability of overall survival at 1 and 3 years was 71.4% (95%CI, 51.3-99.5%) and 64.3% (95%CI, 43.5-95.0%), respectively. The probability of disease-free survival at 1 and 3 years was 71.4% (95%CI, 51.3-99.5%) and 57.1% (95%CI, 36.3-89.9%), respectively. In conclusion, haplo-HSCT is a feasible method for patients with MS who have no MSD or MUD.

Myeloid sarcoma, chloroma, or extramedullary acute myeloid leukemia tumor: A tale of misnomers, controversy and the unresolved

The World Health Organization classification and definition of "myeloid sarcoma" is imprecise and misleading. A more accurate term is "extramedullary acute myeloid leukemia tumor (eAML)." The pathogenesis of eAML has been associated with aberrancy of cellular adhesion molecules, chemokine receptors/ligands and RAS-MAPK/ERK signaling. eAML can present with or without synchronous or metachronous intramedullary acute myeloid leukemia (AML) so a bone marrow evaluation is always recommended. Accurate diagnosis of eAML requires tissue biopsy. eAML confined to one or a few sites is frequently treated with local therapy such as radiotherapy. About 75-90% of patients with isolated eAML will develop metachronous intramedullary AML with a median latency period ranging from 4 to 12 months; thus, patients with isolated eAML may also be treated with systemic anti-leukemia therapy. eAML does not appear to have an independent prognostic impact; selection of post-remission therapy including allogeneic hematopoietic cell transplant (alloHCT) is typically guided by intramedullary disease risk. Management of isolated eAML should be individualized based on patient characteristics as well as eAML location and cytogenetic/molecular features. The role of PET/CT in eAML is also currently being elucidated. Improving outcomes of patients with eAML requires further knowledge of its etiology and mechanism(s) as well as therapeutic approaches beyond conventional chemotherapy, ideally in the context of controlled trials.

Clinical characteristics and management of primary granulocytic sarcoma of the oral cavity: A case report and literature review

INTRODUCTION

Granulocytic sarcoma (GS) is a commonly occurring tumor comprising immature myeloid cells, which are usually related to acute or chronic myelocytic leukemia. The tumor rarely precedes leukemia without bone marrow involvement and is called primary GS. Although primary GS can occur in any body part, the involvement of the oral cavity is uncommon.

PATIENT CONCERNS

A 49-year-old woman hospitalized at the Department of Plastic and Maxillofacial Surgery presented with a growing mass in her left maxillary hard palate dating two months back. No obvious physical findings were noted during general examination. She was diagnosed with an oral ulcer at a local clinic, and received antibiotics. However, the symptoms did not improve; the mass became bigger and painful.

DIAGNOSIS

An incisional biopsy of the oral mass was performed, the immunohistochemistry showed that the tumor cells tested positive for myeloperoxidase, CD4, BCL-2, KI-67. Bone marrow aspiration was negative for malignant cells, and the laboratory test results revealed only monocytosis. Standard bone marrow cytogenetic analysis showed a normal karyotype and leukemia-related fusion gene detection was normal. Therefore, the final diagnosis was intraoral primary GS.

INTERVENTIONS

The patient was treated with a chemotherapy regimen based on idarubicin and cytarabine arabinoside.

OUTCOMES

After 2 cycles of idarubicin and cytarabine arabinoside regimen chemotherapy, the patient achieved complete remission. The tumor was barely visible in the left maxillary hard palate. There has been no evidence of disease spread and progression after 1 year of follow-up.

CONCLUSIONS

Careful morphological and immunohistochemical analyses, correlating with clinical data are necessary to establish the diagnosis of oral primary GS. Early aggressive systemic chemotherapy can effectively relieve symptoms, significantly reducing primary GS conversion into acute myelocytic leukemia and prolonging overall survival.

Extra-medullary recurrence of myeloid leukemia as myeloid sarcoma after allogeneic stem cell transplantation: impact of conditioning intensity

Myeloid sarcoma (MS) as a solid extra-medullary (EM) manifestation of acute myeloid leukemia (AML), myeloproliferative or myelodysplastic syndromes is a rare presentation of relapse after allogeneic hematopoietic stem cell transplantation (HSCT). The databases of the Departments of Hematology and Oncology of the University Hospitals of Jena and Rostock were screened for patients aged 18 years or older for onset of MS after HSCT for myeloid malignancies between 2002 and 2019. Nineteen patients with MS were identified, the majority of whom had received reduced-intensity conditioning (RIC). The median onset of MS was 425 days after HSCT and the median overall survival since MS was 234 days. Although MS is associated with a poor prognosis, three patients survived more than two years and one more than 11 years after MS onset. These results indicate that RIC protocols may be associated with a higher risk of EM relapse. Since EM relapse occurred in the presence of Graft-versus-host-disease, these observations also demonstrate the limitations of graft-versus-tumor effects after HSCT. In conclusion, occurrence of MS after HSCT is associated with a poor prognosis, as multimodal curative concepts including intensive chemotherapy and another HSCT are often not viable.

Myeloid sarcoma

PURPOSE OF REVIEW

Myeloid sarcoma; also known as granulocytic sarcoma and chloroma, often occurs concomitantly with AML, and rarely without bone marrow involvement. In this article, we review the recent literature on myeloid sarcoma, focusing on treatment approach for this rare disease, and addressing the prognostic and therapeutic role of molecular and cytogenetic aberrations.

RECENT FINDINGS

Molecular testing and cytogenetics are important adjunct to conventional diagnostic methods. The significance of cytogenetic and molecular abnormalities in myeloid sarcoma is not completely established, but testing for targetable mutations on myeloid sarcoma cells is feasible, imperative, and may guide treatment decisions. Outcomes in myeloid sarcoma largely depend on the background of its development. Almost all patients with myeloid sarcoma eventually develop AML typically in a short period after its diagnosis; therefore, remission induction treatment using AML type chemotherapy has been the standard of care. Postremission therapy is controversial; allogenic SCT, radiotherapy or consolidation chemotherapy should be considered according to patient risk.

SUMMARY

Further research is required to understand the nature of myeloid sarcoma, and inclusion of patients with this condition in clinical trials should be considered to better identify the best diagnostic, prognostic, and therapeutic approach in managing this rare disease.

Myeloid sarcoma is associated with poor clinical outcome in pediatric patients with acute myeloid leukemia

PURPOSE

The impact of myeloid sarcoma (MS) on clinical outcome of pediatric acute myeloid leukemia (AML) patients remains controversial. Moreover, little is known about the role of stem cell transplantation (SCT) in such patients.

METHODS

Clinical data of patients with AML under 18 years of age were retrieved from the TARGET dataset. We analyzed the prevalence, clinical profile, molecular characteristics, and prognosis of MS in these patients.

RESULTS

Among 884 pediatric patients with AML, the frequency of MS was 12.3%. Pediatric AML with MS was associated with age under 1-year, abnormal cytogenetics, and KMT2A rearrangement. Moreover, MS was associated with a low complete remission rate, high induction death, poor 5-year EFS, and OS. KMT2A rearrangement had a negative impact on clinical outcome in AML patients with MS. In addition, SCT had no significant effect on the survival of AML patients with MS. Multivariate analysis revealed that MS was an unfavorable prognostic factor in pediatric AML in terms of EFS (Hazard ratio 1.670, P < 0.001) and OS (Hazard ratio 1.623, P = 0.004).

CONCLUSIONS

The presence of MS at diagnosis of pediatric AML is associated with poor clinical outcomes, particularly when associated with KMT2A rearrangements. Moreover, pediatric patients with AML and MS may not benefit from SCT.

Primary bronchial myeloid sarcoma mimicking bronchogenic carcinoma: a case report

BACKGROUND

Myeloid sarcoma (MS) rarely involves the bronchus, and primary bronchial MS has almost never been reported in mainland China.

CASE PRESENTATION

A 65-year-old female patient was admitted with a 3-month history of cough. She was initially diagnosed with bronchogenic carcinoma according to chest computed tomography (CT). However, after a biopsy was taken from the endobronchial lesion by bronchoscopy and further immunohistochemical analysis was performed, the diagnosis of MS was made. Because her bone marrow was normal and she had no history of haematologic diseases, we further considered the diagnosis of primary bronchial MS. The patient received chemotherapy with HAG regimens, and the original mass completely resolved, as confirmed by chest CT scan after 3 cycles of treatment. Meanwhile, no abnormalities were found on re-examination via bronchoscopy.

CONCLUSIONS

MS should be considered in the differential diagnosis in the presence of a suspicious pulmonary mass. Immunohistochemical analysis is necessary to confirm the diagnosis. Chemotherapy can lengthen the survival time for patients.

Myeloid Sarcoma

Hematological malignancies can manifest as extramedullary soft tissue masses in relatively rare cases. The rarity of it causes a diagnostic and therapeutic challenge. One of the rarest manifestations is myeloid sarcoma (MS). MS develops as part of acute myeloid leukemia, myeloproliferative neoplasm, or myelodysplastic syndrome or at relapse, especially following allogeneic hematopoietic stem cell transplant. The tumor displays high myeloperoxidase expression, hence the color green, and is called chloroma. It most commonly appears in lymph nodes, skin and soft tissues, bone, testes, gastrointestinal tract, and peritoneum. Immunohistochemistry shows CD68-KP1 as the most commonly expressed marker, then myeloperoxidase, CD117, CD99, CD68/PG-M1, lysozyme, CD34, terminal deoxynucleotidyl transferase, CD56, CD61, CD30, glycophorin A, and CD4. Different chromosomal abnormalities including MLL rearrangement, t(8; 21), monosomy 7, trisomy 8, trisomy 11, trisomy 4, inversion (16), monosomy 16,16q deletion, 5q deletion, and 20q deletion were reported. Most of the literature about MS are case reports and small retrospective studies, thus there is limited clinical knowledge of the cases and their presentation and management plans. Here, we provide a review of what has been reported in the literature about MS in the light of our experiences.

An overview on the differential diagnostics of tumors of the anterior-superior mediastinum: the pathologist's perspective

The thymus is the main organ in the (anterior) (pre-vascular) mediastinum, playing a central role in the maintenance of both cellular and humoral immunity. The function of the thymus has been long underlooked due to its involution starting during young adulthood and unawareness regarding its immunological function. A variety of primary tumors and inflammatory/reactive/disreactive processes occur in the mediastinum and may involve the anterior-superior compartment and the thymus. Maldevelopment processes also take place in the pre-vascular compartment mediastinum. Although infective diseases do not currently represent the main processes in western countries, they may represent a diagnostic challenge in developing countries. The purpose of this review is to provide a short overview of the main thymic cellular components, their tumors, pseudotumors, in order to provide insights into their clinical setting and the features which assist pathologists in their differential diagnosis (DD). Specific differential diagnostic points are provided, both for "solid" tumors as well as for haematological malignancies, together with a morphological overview of cases of concern that occur in the anterior mediastinum. The main immunohistochemical characteristics of neoplastic/non-neoplastic pathology and updated specific references are also provided.

FLT3-ITD Compared with DNMT3A R882 Mutation Is a More Powerful Independent Inferior Prognostic Factor in Adult Acute Myeloid Leukemia Patients After Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective Cohort Study

Objective

This study aimed to evaluate DNMT3A exon 23 mutations and their prognostic impacts in the presence of NPM1 and FLT3 mutations in acute myeloid leukemia (AML) patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT).

Materials and Methods

This study comprised 128 adult AML patients referred to the Hematology-Oncology and Stem Cell Research Center of Shariati Hospital. NPM1 and FLT3-ITD mutations were detected by fragment analysis. For DNMT3A exon 23 mutation analysis, we used Sanger sequencing. Overall survival (OS) and relapse-free survival (RFS) curves were estimated by the Kaplan-Meier method and the log-rank test was used to calculate differences between groups.

Results

The prevalence of DNMT3A exon 23 mutations was 15.6% and hotspot region R882 mutations were prominent. RFS and OS were compared in patients with and without DNMT3A exon 23 mutations using univariate analysis and there was no significant difference between these groups of patients. On the contrary, the FLT3-ITD mutation significantly reduced the OS (p=0.009) and RFS (p=0.006) in AML patients after allogeneic HSCT. In the next step, patients with AML were divided into four groups regarding FLT3-ITD and DNMT3A mutations. Patients with DNMT3A R882mut/FLT3-ITDpos had the worst OS and RFS. These results indicate that DNMT3A mutations alone do not affect the clinical outcomes of AML patients undergoing allogeneic HSCT, but when accompanied by FLT3-ITD mutations, the OS was significantly reduced (5-year OS 0% for DNMT3A R882mut/FLT3-ITDpos patients vs. 62% DNMT3A R882wt/FLT3-ITDneg, p=0.025) and the relapse rate increased.

Conclusion

It can be deduced that DNMT3A R882mut/FLT3-ITDpos is an unfavorable prognostic factor in AML patients even after allogeneic HSCT.

Myeloid sarcoma with megakaryoblastic differentiation presenting as a breast mass

Myeloid sarcoma is an extramedullary tumor that consists of myeloblasts or immature myeloid cells. The neoplasm can occur in any part of the body, including the bone, periosteum, lymph nodes, skin, and soft tissue and they may occur de novo or in association with acute myeloid leukemia, myeloproliferative neoplasms and myelodysplastic syndromes. Most cases display a myelomonocytic or pure monoblastic morphology. Tumors with megakaryoblastic differentiation are extremely uncommon and may occur in association with transformation of a myeloproliferative disorder. Myeloid sarcoma presenting as a breast mass is very rare and diagnostically challenging. We report a case of myeloid sarcoma with megakaryoblastic differentiation in the breast of a patient with history of essential thrombocythemia. The mass was composed of undifferentiated pleomorphic malignant cells in trabecular cords and nests with many scattered giant malignant cells and brisk abnormal mitoses. On immunohistochemistry, the neoplastic cells were positive for CD61, CD31, CD34, Factor VIII and CD43 which confirmed the diagnosis. To our knowledge, this is the first report of myeloid sarcoma with megakaryoblastic morphology occurring in the breast. Here we discuss the clinicopathologic features of this rare entity and the challenges involved in making this difficult diagnosis.

Isolated Pancreatic Myeloid Sarcoma Associated with t(8;21)/RUNX1-RUNX1T1 Rearrangement

No valid treatment for isolated myeloid sarcoma (IMS) has yet been established, and no thorough genetic examinations have been performed because of its low incidence and unique manner of development. We herein report a 34-year-old man with pancreatic IMS with t(8;21)/RUNX1-RUNX1T1 rearrangement. He was treated with high-dose cytarabine followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). This is the first report of pancreatic IMS with t(8;21). Positron emission tomography/computed tomography and genetic study are useful for the diagnosis, and allo-HSCT achieved complete remission in this patient.

Radiotherapy for isolated granulocytic sarcoma: Case report and review of literature

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Isolated chloroma should be considered as a systemic disease.

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Consolidation radiotherapy has been related with prolonged failure free survival.

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Excellent local control of chloroma is achieved with low-dose radiotherapy.

A Rare Case of Pure Erythroid Sarcoma in a Pediatric Patient: Case Report and Literature Review

We describe an exceptional case of erythroid sarcoma in a pediatric patient as a growing orbital mass with no evidence of morphologic bone marrow involvement, who was finally diagnosed of pure erythroid sarcoma based on histopathology and flow cytometry criteria. We discuss the contribution of standardized eight-color flow cytometry as a rapid and reliable diagnostic method. The use of normal bone marrow databases allowed us to identify small aberrant populations in bone marrow and later confirm the diagnosis in the neoplastic tissue.

Clinical characteristics and treatment outcomes of isolated myeloid sarcoma without bone marrow involvement: a single-institution experience

Background

Isolated myeloid sarcoma (MS) is a rare extramedullary tumor mass composed of malignant myeloid precursor cells without any evidence of leukemia in the peripheral blood and bone marrow. We describe the clinical characteristics and outcomes of patients diagnosed with isolated MS at our institution.

Methods

We retrospectively reviewed 9 of 497 acute myeloid leukemia (AML) patients (1.8%) with isolated MS. Isolated MS patients were divided into 2 groups according to the first-line treatment strategy: systemic treatment only (S) or local treatment with or without systemic treatment (LS).

Results

The most common site of MS occurrence was the head and neck area (N=4, 44.4%), followed by the anterior mediastinum (N=2, 22.2%) and the gastrointestinal tract (N=2, 22.2%). The tumors of 4 patients (44.4%) eventually evolved to AML, in a median time of 13.4 months (range, 2.4–20.1 mo). The number of patients achieving complete remission after first-line treatment was higher in the LS group (N=5, 83.3%) than in the S group (N=1, 33.3%) (P =0.226). All patients in the LS group survived, but those in the S group died (P=0.012).

Conclusion

Accurate and rapid diagnosis using various modalities and the early initiation of intensive combined treatment may be the optimal strategies to reduce the risk of isolated MS subsequently evolving to AML. To fully understand the characteristics of isolated MS, a larger number of patients from a multinational study is necessary.

Isolated myeloid sarcoma as the first manifestation of acute myeloid leukemia: a case study

This case report brings awareness to the diverse extramedullary manifestations of isolated myeloid sarcoma, as well as the importance and difficulties that are associated with establishing a rapid diagnosis and initiating treatment.

Myeloid Sarcoma: Presentation, Diagnosis, and Treatment

Myeloid sarcoma is an extramedullary tumor of immature granulocytic cells. It is a rare condition, most often associated with acute myeloid leukemia (AML), although in some rare cases it may present in nonleukemic patients. It should therefore be considered as a differential diagnosis of any atypical cellular infiltrate. It may occur at any site, leading to very varied clinical presentations. Diagnosis is challenging and relies on a high index of suspicion as well as radiology, histology, immunophenotyping, and molecular analyses, which also are essential for risk stratification and treatment planning. Systemic chemotherapy using AML-like regimens should be commenced early, even in nonleukemic disease. Surgery and/or radiotherapy may be indicated for symptomatic lesions or tumors causing local organ dysfunction or obstruction. Allogeneic hematopoietic stem cell transplantation has demonstrated promising results, particularly in patients who achieved complete remission with AML-induction protocols, and recent advances in genetic profiling may enable the development of novel targeted therapies. Prospective multicenter controlled trials are required to further refine management decisions and investigate the role of novel targeted therapies.

Long-Term Remission following Autologous Hematopoietic Cell Transplantation in a Patient with Multiple Nonleukemic Myeloid Sarcoma and a Review of the Literature

Multiple nonleukemic myeloid sarcoma (MS) is a rare form of MS that is developed in multiple anatomic sites other than bone marrow at diagnosis, without a preceding myeloid neoplasm. The prevalence, prognosis, and optimal management of multiple nonleukemic MS have not been addressed. The role of allogenic or autologous hematopoietic cell transplantation (HCT) for nonleukemic MS is also less well defined. We present a case of MS characterized by systemic lymphadenopathies and multiple effusions, which presumably had a very poor prognosis. The patient was treated with acute myeloid leukemia-type induction chemotherapy and autologous peripheral blood stem cell transplantation, and, unexpectedly, she has remained disease free for more than 6 years. We also reviewed the literature on this rare disease, and found that multiple nonleukemic MS was associated with younger age and a worse prognosis when compared with the overall nonleukemic MS population. We suggest that autologous HCT represents a valid option for young patients with chemosensitive disease and should be performed at the status of minimal residual disease-negative complete remission.

Myeloid sarcoma in children - diagnostic and therapeutic difficulties

Myeloid sarcoma (MS) is a malignant extramedullary tumour, which consists of immature cells of myeloid origin. It may occur de novo, concurrently or precede the diagnosis of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) or chronic myeloid leukemia (CML). MS can also be a manifestation of the relapse of the disease. The more frequent sites of involvement are the skin, orbit, bone, periosteum, lymph nodes, gastrointestinal tract, soft tissue, central nervous system and testis. Because of its different localization and symptoms, and the lack of diagnostics algorithm, myeloid sarcoma is a real diagnostic challenge, in particular in patients without initial bone marrow involvement. The correct diagnosis of MS is important for adequate therapy, which is often delayed because of a high misdiagnosis rate. In the paper, the role of immunohistochemistry, cytogenetic and molecular genetic analyses is emphasized as well as the breadth of unclear aspects of this disorder in children.

Clinical outcome of myeloid sarcoma in adult patients and effect of allogeneic stem cell transplantation. Results from a multicenter survey

INTRODUCTION

Myeloid Sarcoma (MS) is a rare hematologic myeloid neoplasm that can involve any site of the body. It can occur as an exclusively extramedullary form or it can be associated with an acute myeloid leukemia (AML), a chronic myeloproliferative neoplasm (MPN) or a myelodysplastic syndrome (MDS) at onset or at relapse. The rarity of MS does not enable prospective clinical trials and therefore a specific multicenter register can be useful for the clinical and biological studies of this rare disease.

PATIENTS AND RESULTS

we report the clinical characteristics and outcome of 48 histologically confirmed MS, diagnosed and treated in 9 Italian Hematological Centers in the last 10 years. The patient's median age was 46 years. There were 9/48 de novo extramedullary MS, 24/48 de novo AML-related MS and 15/48 were secondary AML-related MS. The most common extramedullary anatomic sites of disease were: skin, lymph nodes and soft tissues. Forty-three patients (90%) underwent a program of intensive chemotherapy including FLAI, HDAC-IDA, HyperCVAD and MEC schemes, with a DDI of 5% and a CR Rate of 45%. Twenty-two (46%) patients underwent Allogeneic SCT, 13 from a MUD, 8 from an HLA-identical sibling donor and 1 from an haploidentical donor. The median OS of the whole population (48 pts) was 16.7 months. The OS probability at 1, 2 and 5 years was 64%, 39% and 33%, respectively. The OS was better in patients that underwent an intensive therapeutic program (median OS: 18 months vs 5 months). Among the intensively treated patients, in univariate analysis, the OS was better in young patients (P=0,008), in patients that underwent Allo-SCT (P=0,009) and in patients that achieved a CR during treatment (P=0,001), and was worse in pts with secondary AML-related MS (P=0,007). Age, response to intensive chemotherapy and Allo-SCT were the only three variables that significantly influenced DFS (P=0,02, P=0,01 and P=0,04, respectively). In multivariable analysis, Allo-SCT and response to intensive chemotherapy remained significant in predicting a better OS (P=0,04 and P=0,001, respectively), and response to intensive chemotherapy was the only significant variable in predicting DFS (P=0,01). After Allo-SCT we observe a survival advantage in patients who achieved a pre-transplant CR (P=0,008) and in those who developed a chronic GvHD (P=0,05).

CONCLUSIONS

Patients with MS, both with de novo and secondary forms, still have a very unfavorable outcome and require an intensive therapeutic program, that includes Allo-SCT whenever possible. The outcome after Allo-SCT is positively influenced by the development of chronic GvHD suggesting a Graft versus MS effect.

Characteristics and Survival Outcome Analysis of Extramedullary Involvement in Adult Patients With t(8;21) Acute Myeloid Leukemia

BACKGROUND

Acute myeloid leukemia (AML) with t(8;21)(q22;q22) is classified into a favorable-risk group. Extramedullary (EM) involvement has frequently been reported in this subgroup as resulting in a poor prognosis. However, characteristics or standard treatments of t(8;21) AML with EM involvement (EM-positive t(8;21)) have not yet been elucidated.

PATIENTS AND METHODS

We retrospectively analyzed 154 adult AML patients with t(8;21). Among them, 17 were EM positive and 137 were EM negative at the time of diagnosis. EM involvement was evaluated only when a patient showed suspicious signs or symptoms. All EM-positive patients were treated according to a strategy based on allogeneic hematopoietic cell transplantation (allo-HCT).

RESULTS

Central nervous system was the most frequently involved site (70.6%). EM-positive t(8;21) was associated with age ≤ 45 years, leukocytosis (≥ 30 × 10⁹/L), and c-kit mutation compared to EM-negative t(8;21) in multivariate analysis. After intensive chemotherapy with or without local therapy, high-risk t(8;21) AML including EM-positive t(8;21) underwent allo-HCT for postremission therapy. Three-year OS (52.3% vs. 60.0%, P = .658) and event-free survival (51.5% vs. 58.0%, P = .496) were not different between the 2 groups. The subgroup of patients who underwent allo-HCT also showed similar outcomes.

CONCLUSION

EM-positive t(8;21) was associated with young age, leukocytosis, and c-kit mutation, and central nervous system was frequently involved. Allo-HCT resulted in good outcomes in EM-positive t(8;21).

Myeloid Sarcoma of the Hepatobiliary System: A Case Series and Review of the Literature

Myeloid sarcoma (MS) is a rare extramedullary presentation of myeloid malignancies, most commonly seen in association with acute myeloid leukemia (AML). Although MS can develop in any organ, the involvement of the hepatobiliary system is rare. With clinical manifestations of jaundice, abdominal pain and other gastrointestinal symptoms, MS presenting at this location can be a challenge to diagnose, particularly in patients with no known history of hematologic malignancy. This may cause delay in proper management. Here we report 3 cases from a single institution and a review of the literature concerning the epidemiology, clinical presentation, treatment and outcomes in patients with MS of the liver, biliary tree and pancreas.

Extramedullary Manifestations of Myeloid Neoplasms

OBJECTIVES

This session of the 2013 Society of Hematopathology/European Association for Haematopathology workshop focused on extramedullary manifestations of myeloid neoplasms.

METHODS

We divided the submitted cases into four subgroups: (1) isolated myeloid sarcoma (MS); (2) MS with concurrent acute myeloid leukemia (AML), with a focus on karyotypic and molecular findings; (3) extramedullary relapse of AML, including relapse in the posttransplant setting; and (4) blast phase/transformation of a myeloproliferative neoplasm or chronic myelomonocytic leukemia.

RESULTS

Establishing a diagnosis of isolated MS requires a high index of suspicion and use of immunophenotypic methods. Recurrent cytogenetic abnormalities or gene mutations that occur in MS mirror those known to occur in AML.

CONCLUSIONS

In the era of targeted therapy and sophisticated risk stratification, every attempt must be made to perform a complete workup on MS cases (or concurrent AML) since the diagnosis of MS, in itself, is no longer adequate for patient management. Cases of blastic plasmacytoid dendritic cell neoplasm were also included and discussed in this session.

Granulocytic sarcoma in a patient with chronic myeloid leukaemia in complete haematological, cytogenetic and molecular remission

Granulocytic sarcoma, also known as myeloid sarcoma, is an extramedullary tumour composed of immature myeloid cells. Granulocytic sarcoma is typically found in patients with acute myeloid leukaemia, accelerated phase or blast crisis of chronic myeloid leukaemia, myelodysplastic syndrome, or as an isolated event without bone marrow involvement. We present a case of granulocytic sarcoma in a patient with chronic myeloid leukaemia in the setting of complete haematological, molecular and cytogenetic remission. Our patient was first treated with imatinib for chronic-phase chronic myeloid leukaemia. After maintaining remission for 42 months, he developed a granulocytic sarcoma in his spine. In this case report, we describe our case, along with the three other cases reported in the literature. In addition to being a rare diagnosis, this case demonstrates the importance of being vigilant in diagnosing the cause of back pain and atypical symptoms in patients with a history of leukaemia.

Isolated myeloid sarcoma of the neck and chest: differential diagnosis and therapeutic approach

In this article, we present the case of a 57-year-old man with cervical and mediastinal tumor mass, normal blood count as well as virusological status. Cervical tumor tissue biopsy revealed cells positive for CD34, CD13, LCA, CD33, and CD163 but negative for T-cell and B-cell markers, NK-cell markers, plasmacytic markers and anaplastic large cell lymphoma markers. These features were consistent with myeloid sarcoma of the neck with involvement of the mediastinum. We discussed differential diagnosis and therapy of isolated myeloid sarcoma and suggest that clinical presentation, cell morphology, complete immunophenotype, and specific genotypic lesions in some cases, must be evaluated.

Isolated gastric myeloid sarcoma: a case report and review of the literature

Myeloid sarcoma represents the proliferation of myeloblasts of acute myeloid leukemia (AML) at extramedullary sites. While extramedullary involvement in AML is uncommon in itself, isolated myeloid sarcomas, that is, myeloid sarcomas without any bone marrow involvement, are extremely rare and pose a diagnostic and therapeutic challenge. Here, we present the case of a middle-aged woman with isolated myeloid sarcoma in the stomach-an organ seldom involved by this disease. Additionally, the literature on the epidemiology, diagnosis, pathology, prognosis, and therapeutic options in myeloid sarcomas has been reviewed.

Rapid remineralization of multiple disseminated bone lesions after high-dose cytarabine in a patient with isolated myeloid sarcoma

Isolated myeloid sarcoma is a rare presentation of acute myeloid leukemia. There are limited data available concerning the prognostic relevance and the right treatment strategy for this clinical scenario. Here, we report a case of acute myeloid leukemia with extensive lesions and fractures in multiple bones in a 64-yr-old male patient. Remarkably, treatment with a high-dose cytarabine regimen led to rapid remineralization of all bone lesions and recovery of the patient's mobility within a few weeks. Thereby, surgical treatment and radiotherapy could be avoided, supporting the role of intensive induction and standard consolidation chemotherapy as first-line treatment for myeloid sarcoma.

Granulocytic sarcoma: a systematic review

Granulocytic sarcoma also called myeloid sarcoma is an extramedullary tumor of immature granulocytic cells. It is a rare entity, and mostly accompanied by acute myeloid leukemia. It is observed during the course of myeloproliferative disorders especially in chronic myeloid leukemia and myelodysplastic syndromes. In some rare circumstances, it is detected before clinical signs of leukemia or other diseases. When the bone marrow biopsy reveals no other hematologic malignancies, the granulocytic sarcoma is described as nonleukemic, primary or isolated. It is observed at any part of the body but the most common locations are soft tissues, bone, peritoneum and lymph nodes. Presenting signs or symptoms are mainly due to mass effect of the tumor and dysfunction of the organ, or the tissue that is affected. The diagnosis is performed by biopsy of the tumor. The tumor consists of immature granulocytic cells, which could be documented by H&E, immunohistochemistry, and flow cytometric methods. Fluorescence in-situ hybridization and molecular analysis are also performed. The optimal time and type of treatment is not clear. Surgery could be an option especially for tumors, which cause organ dysfunction and/or obstruction. Systemic treatment should be considered in all patients because without systemic treatment, relapses and progression to acute myeloid leukemia is the ultimate fate of the disease in many cases. Cytarabine-containing remission-induction chemotherapies have been the most applied therapeutic strategies, but it is not clear whether the consolidation therapies are required or not, and what kind of regimens are appropriate. The role of hematopoietic stem cell transplantation (HSC) as a consolidation regimen is not clear, but, after the relapse of the disease with or without bone marrow involvement, HSC transplantation should be considered in suitable patients after the reinduction performed by AML chemotherapies. There is only limited data about the role of radiotherapy in these patients. It could be used in patients with relapsed disease, organ dysfunction which should be quickly relieved and inadequate response to chemotherapy. The effect of radiotherapy on overall survival is not known. New prospective studies and clinical trials are needed to generate guidelines for the treatment of primary granulocytic sarcomas.