Multiple extramedullary relapses without bone marrow involvement after second allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia

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.

Different Kinetics and Risk Factors for Isolated Extramedullary Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Acute Leukemia

Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most frequent cause of post-transplantation mortality. Isolated extramedullary (EM) relapse (iEMR) after HSCT is relatively rare and not well characterized, particularly in pediatric patients. We retrospectively analyzed 1527 consecutive pediatric patients with acute leukemia after allo-HSCT to study the incidence, risk factors, and outcome of iEMR compared with systemic relapse. The 5-year cumulative incidence of systemic relapse (either bone marrow [BM] only or BM combined with EMR) was 24.8%, and that of iEMR was 5.5%. The onset of relapse after allo-HSCT was significantly longer in EM sites than in BM sites (7.19 and 5.58 months, respectively; P = .013). Complete response (CR) 2+/active disease at transplantation (hazard ratio [HR], 3.1; P < .001) and prior EM disease (HR, 2.3; P = .007) were independent risk factors for iEMR. Chronic graft-versus-host disease reduced the risk of systemic relapse (HR, 0.5; P = .043) but did not protect against iEMR. The prognosis of patients who developed iEMR remained poor but was slightly better than that of patients who developed systemic relapse (3-year overall survival, 16.5% versus 15.3%; P = .089). Patients experiencing their first systemic relapse continued to have further systemic relapse, but only a minority progressed to iEMR, whereas those experiencing their iEMR at first relapse developed further systemic relapse and iEMR at approximately similar frequencies. A second iEMR was more common after a first iEMR than after a first systemic relapse (58.8% versus 13.0%; P = .001) and was associated with poor outcome. iEMR has a poor prognosis, particularly after a second relapse, and effective strategies are needed to improve outcomes.

Myeloid sarcoma of the heart: Extramedullary relapse of acute myeloblastic leukemia, presenting with complete heart block and atrial flutter after second allogeneic stem cell transplantation

We report isolated extramedullary relapse in a 14-year-old boy, sequentially presenting with intestinal and cardiac myeloid sarcoma (MS). Acute myeloblastic leukemia M5 was diagnosed 41 months ago. On the 14th month of the second HSCT, he presented with ileus and underwent surgical treatment. After 2 weeks, arrhythmia, bradycardia, complete heart block, and atrial flutter developed and echocardiography revealed multiple cardiac masses. There was no bone marrow relapse but pathology of the intestinal biopsy showed leukemic infiltration. Patient was successfully treated with a permanent pacemaker and salvage chemotherapy. To the best of our knowledge, this is the first pediatric cardiac MS developed after HSCT.

Oral myeloid sarcoma as an uncommon manifestation of acute myeloid leukemia: A case series and review of the literature

BACKGROUND AND OVERVIEW

Oral myeloid sarcoma (MS) is an extramedullary tumor that can occur in the setting of acute myeloid leukemia, either as the first sign of an underlying disease or later in the course of disease. The authors' aim was to present the clinical features of oral MS and review the literature.

CASE DESCRIPTION

Case 1 was an 82-year-old woman with an asymptomatic erythematous swelling on the maxillary gingiva and no history of hematologic malignancy. Case 2, a 65-year-old man, and case 3, a 58-year-old woman, each had a history of acute myeloid leukemia and a painful ulcer on the palatal mucosa and an asymptomatic ulcer on the lower lip mucosa, respectively. Case 1 was treated with focal radiation then chemotherapy and achieved complete remission initially, but died of relapse 2 years after diagnosis. Case 2 received radiotherapy and immunotherapy and had a complete response. Case 3 received chemotherapy and achieved remission initially, but relapsed and is undergoing investigational targeted therapies.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Oral MS can manifest as gingival or mucosal swelling or ulceration and can indicate onset or relapse of associated hematologic malignancies, which often have a poor prognosis. Because patients with oral findings are likely to seek treatment from their dentists first, oral clinicians should maintain a broad differential diagnosis list when evaluating oral lesions, especially if treatment prescribed for a more common diagnosis fails to resolve the lesion.

Applications of PET in Diagnosis and Prognosis of Leukemia

As a malignant hematopoietic stem cell disease, leukemia remains life-threatening due to its increasing incidence rate and mortality rate. Therefore, its early diagnosis and treatment play a very important role. In the present work, we systematically reviewed the current applications and future directions of positron emission tomography (PET) in patients with leukemia, especially ¹⁸F-FDG PET/CT. As a useful imaging approach, PET significantly contributes to the diagnosis and treatment of different types of leukemia, especially in the evaluation of extramedullary infiltration, monitoring of leukemia relapse, detection of Richter’s transformation (RT), and assessment of the inflammatory activity associated with acute graft versus host disease. Future investigations should be focused on the potential of PET/CT in the prediction of clinical outcomes in patients with leukemia and the utility of novel radiotracers.

A case of myeloid sarcoma of the mandibular gingiva as extramedullary relapse of acute myeloid leukemia

PURPOSE

Myeloid sarcoma (MS) is defined as a tumorous mass of myeloblasts or immature myeloid cells involving an extramedullary anatomic site. MS occurs in 3 to 8% of patients with acute myeloid leukemia. The overwhelming majority of MS occurs in the skin, bones, and gastrointestinal tract; intraoral MS (IMS) is extremely rare.

METHODS

We describe a case of MS of the mandibular gingiva in a patient with acute myeloid leukemia that was in remission. We also present a review of the English and Japanese literature with a special focus on the management and prognosis of intraoral MS.

RESULTS

The patient was discharged while in remission 8 months after the initial examination.

CONCLUSION

The prognosis of IMS is extremely poor in general, and a diagnostic delay can prevent adequate therapy by hematologists and oncologists. All dental clinicians must keep the possibility of IMS in mind and carefully examine all patients with AML.

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.

Relapse of Biphenotypic Acute Leukemia as a Breast Mass

In acute leukemia, leukemic infiltration of the breast is extremely rare. We report a case of biphenotypic acute leukemia (BAL) that presented as a breast mass. A 30-year-old woman presented with a 4-month history of a right breast mass with nipple discharge and easy fatigue. She had received chemotherapy and peripheral blood stem cell transplantation for BAL and had been in complete remission for the last 2 years. Core needle biopsy of the breast mass revealed monomorphous infiltrates of blast cells with round nuclei and fine chromatin, consistent with leukemic infiltration. Subsequent bone marrow biopsy showed diffuse infiltration of immature cells. However, bone marrow karyotyping showed 46, XY, suggesting complete engraftment of transplanted donor cells. This is the report of BAL recurring as a breast mass. In the differential diagnosis of a breast mass, extramedullary relapse should be considered when the patient has a history of leukemia.

Use of 18F-FDG PET-CT for Detection of Active Disease in Acute Myeloid Leukemia

A 4-year-old girl with history of acute myeloid leukemia post chemotherapy and stem cell transplant presented with pancytopenia. F-FDG PET-CT (PET-CT) showed multiple metastatic bone and extra medullary soft tissue lesions. Bone marrow biopsy after additional chemotherapy was negative. Concurrent FDG PET-CT demonstrated hypermetabolic foci in the left thigh and hand consistent with residual soft tissue disease. These lesions resolved after further treatment, but a subsequent PET-CT identified a new site of biopsy-proven chloroma. This case illustrates the important role of FDG PET-CT in identifying clinically undetectable extramedullary sites of disease, which may impact subsequent clinical management.

FDG-PET/CT for Detection of Extramedullary Disease in 2 Pediatric Patients With AML

Positron emission tomography combined with computed tomography (PET/CT) is a promising diagnostic procedure for the detection of extramedullary disease (EMD) in acute myeloid leukemia. We studied 2 children with acute myeloid leukemia who underwent PET to assess for EMD at diagnosis as well as in remission. We detected 5 EMD lesions in 2 cases with PET, only 2 of which were detectable on clinical examination. Our cases show PET's increased sensitivity over physical examination alone in assessing and monitoring the extent of this disease.

Usefulness and pitfalls of F-18-FDG PET/CT for diagnosing extramedullary acute leukemia

PURPOSE

It is very important to identify whether there is extramedullary involvement in acute leukemia (AL), especially in those with recurrent disease. This retrospective study aimed to assess the role of (18)F-FDG PET/CT for diagnosing extramedullary AL.

MATERIALS AND METHODS

PET/CT examinations were performed in 9 patients with newly diagnosed AL, and 70 patients suspected to have recurrent AL. All the patients were diagnosed with AL by bone marrow biopsy. The diagnosis of extramedullary lesions was established according to the combination of pathology, physical examination, and imaging techniques including magnetic resonance imaging (MRI) and PET/CT, and/or cerebrospinal fluid (CSF) cytologic testing, and clinical follow-up.

RESULTS

Of the 79 patients, including 34 acute lymphocytic leukemia (ALL) and 45 acute myeloid leukemia (AML) cases, 30 patients were diagnosed with extramedullary AL. (18)F-FDG PET/CT demonstrated (18)F-FDG positive lesions in the extramedullary regions in 42 patients. Among them, 28 patients were diagnosed to have extramedullary AL and the other 14 were diagnosed with non-hematological malignancies (false positive disease). The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT in diagnosing extramedullary involvement of AL were 93.3% (28/30), 71.4% (35/49), and 79.7%, respectively. The (18)F-FDG uptake of lesions was not significantly different between extramedullary AL and false positive cases (SUVmax: 6.66 ± 2.65 vs. 5.85 ± 1.88, t=1.275, P=0.206). The FDG uptake of extramedullary AL between ALL and AML were also not significantly different (SUVmax: 7.01 ± 2.82 vs. 6.10 ± 2.29, t=1.332, P=0.188). The predominant locations of extramedullary AL were the spleen, soft tissue, lymph nodes, central nerve system, liver, testis, and kidney. A total of 48.2% (27/56) of extramedullary AL lesions presented as diffuse FDG uptake compared with 6.25% (1/16) in the false positive lesions (χ(2)=9.221, P=0.002).

CONCLUSION

(18)F-FDG PET/CT is a sensitive, but not specific imaging modality for diagnosing extramedullary AL. Diffuse (18)F-FDG uptake in extramedullary lesions may indicate leukemia involvement.

Extramedullary relapse of the AML transformed from MDS following auto-HSCT: a case report

The treatment for AML (Acute myeloid/myelogenous leukemia) transformed from MDS (myelodysplastic syndrome) is difficult and controversial clinically, especially in elder patients. In this case report, we diagnosed a 59-year-old female patient with AML-M2a transformed form MDS which might be caused by her chemotherapy for mastocarcinoma. After achieving complete remission (CR) through combined chemotherapy, autologous peripheral blood stem cell transplantation (auto-PBSCT) was attempted. Following auto-HSCT, marrow showed continuous CR but the patient later developed extramedullary bone-infiltration relapse. Then local radiotherapy has been applied, and the patient now has prolonged survival. This is the first (or a successful) case report of auto-HSCT in an elderly patient with AML transformed from MDS.

Extramedullary relapse of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation: an easily overlooked but significant pattern of relapse

Acute myeloid leukemia may manifest as myeloid sarcoma in a variety of extramedullary (EM) tissues at diagnosis or at relapse. Although EM relapse after allogeneic hematopoietic stem cell transplantation (alloSCT) has been considered to be rare, recent studies have suggested that it occurs in 5% to 12% of patients who receive alloSCT, accounting for 7% to 46% of total relapses. The incidence of EM relapse after immunomodulation (eg, donor lymphocyte infusion) or a second SCT is even higher. Moreover, patients with EM relapse are more likely to have had preceding acute graft-versus-host disease or chronic graft-versus-host disease relative to those with bone marrow relapse. Collectively, these observations suggest that the preferential occurrence of the graft-versus-leukemia effect underlies the pathogenesis of EM relapse. Establishing an early diagnosis of EM relapse has been challenging because of the immense diversity in the relapse sites; however, recent studies have suggested the usefulness of (18)F-fluorodeoxyglucose positron emission tomography scans in the detection of EM relapse. As a treatment for EM relapse, a combination of local and systemic therapy should be considered, because local therapy alone often results in subsequent systemic relapse. The prognosis for patients who develop EM relapse after SCT remains poor but is slightly better than that after bone marrow relapse. In addition to an early diagnosis with new modalities, clinical studies using new agents that may offer systemic activity while preserving the graft-versus-leukemia effect are warranted as part of an effort to improve the clinical outcome.