Extramedullary lesions in non-lymphocytic leukemia: results of radiation therapy

Consolidative Proton Radiotherapy for Pediatric Extramedullary Ocular Acute Myeloid Leukemia

Purpose

Pediatric acute myeloid leukemia (AML) often involves extramedullary sites, which can be resistant to standard induction chemotherapy. Consolidative radiation therapy can be used in select cases to improve local control rates and help bridge patients to curative stem cell transplants. However, there is no previously published data to support the use of proton radiotherapy (PT) in this setting. We present radiographic findings and pathologic outcomes of the first reported patient with extramedullary ocular AML to be treated with PT.

Patients and Methods

Details regarding diagnostic evaluation and treatment were obtained from the electronic medical records at the University of Florida Proton Therapy Institute, Nemours Children's Health, and St. Joseph's Children's Hospital.

Results

This 7-month-old patient presented with biopsy-proven relapsed AML in the bilateral anterior chambers of the eyes, which did not resolve with induction chemotherapy. The patient then received PT to a dose of 24 cobalt gray equivalent to both eyes and was found to have no evidence of disease following treatment.

Conclusion

This case provides further evidence that consolidative radiotherapy may be considered for select patients with extramedullary AML who have limited response to induction chemotherapy. Given the increased prevalence of extramedullary AML in pediatric patients, it is worth considering the utilization of PT to mitigate damage to nearby organs and the risk of secondary malignancies.

Myeloid sarcoma: more and less than a distinct entity

Myeloid sarcoma (MS) is a distinct entity among myeloid neoplasms defined as a tumour mass of myeloid blasts occurring at an anatomical site other than the bone marrow, in most cases concomitant with acute myeloid leukaemia (AML), rarely without bone marrow involvement. MS may also represent the blast phase of chronic myeloproliferative neoplasms (MPN) and myelodysplastic syndromes (MDS). However, the clinical and molecular heterogeneity of AML, as highlighted by the 2022 World Health Organization (WHO) and International Consensus (ICC) classifications, indirectly define MS more as a set of heterogeneous and proteiform diseases, rather than a homogeneous single entity. Diagnosis is challenging and relies mainly on histopathology, immunohistochemistry, and imaging. Molecular and cytogenetic analysis of MS tissue, particularly in isolated cases, should be performed to refine the diagnosis, and thus assign prognosis guiding treatment decisions. If feasible, systemic therapies used in AML remission induction should be employed, even in isolated MS. Role and type of consolidation therapy are not univocally acknowledged, and systemic therapies, radiotherapy, or allogeneic hematopoietic stem cell transplantation (allo-HSCT) should be considered. In the present review, we discuss recent information on MS, focusing on diagnosis, molecular findings, and treatments also considering targetable mutations by recently approved AML drugs.

Total marrow irradiation (TMI): Addressing an unmet need in hematopoietic cell transplantation - a single institution experience review

Purpose

TMI utilizes IMRT to deliver organ sparing targeted radiotherapy in patients undergoing hematopoietic cell transplantation (HCT). TMI addresses an unmet need, specifically patients with refractory or relapsed (R/R) hematologic malignancies who have poor outcomes with standard HCT regimens and where attempts to improve outcomes by adding or dose escalating TBI are not possible due to increased toxicities. Over 500 patients have received TMI at this center. This review summarizes this experience including planning and delivery, clinical results, and future directions.

Methods

Patients were treated on prospective allogeneic HCT trials using helical tomographic or VMAT IMRT delivery. Target structures included the bone/marrow only (TMI), or the addition of lymph nodes, and spleen (total marrow and lymphoid irradiation, TMLI). Total dose ranged from 12 to 20 Gy at 1.5-2.0 Gy fractions twice daily.

Results

Trials demonstrate engraftment in all patients and a low incidence of radiation related toxicities and extramedullary relapses. In R/R acute leukemia TMLI 20 Gy, etoposide, and cyclophosphamide (Cy) results in a 1-year non-relapse mortality (NRM) rate of 6% and 2-year overall survival (OS) of 48%; TMLI 12 Gy added to fludarabine (flu) and melphalan (mel) in older patients (≥ 60 years old) results in a NRM rate of 33% comparable to flu/mel alone, and 5-year OS of 42%; and TMLI 20 Gy/flu/Cy and post-transplant Cy (PTCy) in haplo-identical HCT results in a 2-year NRM rate of 13% and 1-year OS of 83%. In AML in complete remission, TMLI 20 Gy and PTCy results in 2-year NRM, OS, and GVHD free/relapse-free survival (GRFS) rates of 0%, 86·7%, and 59.3%, respectively.

Conclusion

TMI/TMLI shows significant promise, low NRM rates, the ability to offer myeloablative radiation containing regimens to older patients, the ability to dose escalate, and response and survival rates that compare favorably to published results. Collaboration between radiation oncology and hematology is key to successful implementation. TMI/TMLI represents a paradigm shift from TBI towards novel strategies to integrate a safer and more effective target-specific radiation therapy into HCT conditioning beyond what is possible with TBI and will help expand and redefine the role of radiotherapy in HCT.

Strahlentherapeutische Behandlung von Leukämien

Hintergrund

Ziel der Arbeit

Material und Methoden

Ergebnisse

Schlussfolgerung

Strahlentherapeutische Behandlung von Leukämien

Hintergrund

Lymphoide Zellen weisen eine hohe Strahlensensitivität auf, sodass die Strahlentherapie eine sinnvolle Ergänzung der Systemtherapie bei Leukämien darstellt. Vor allem als konditionierende Behandlung vor allogener Stammzelltransplantation ist die Radiotherapie in Form einer Ganzkörperbestrahlung etabliert.

Ziel der Arbeit

Die vorliegende Arbeit ermöglicht einen Überblick über Durchführung und Nebenwirkungen der strahlentherapeutischen Behandlung bei Leukämien. Hierbei werden insbesondere die (Langzeit‑)Nebenwirkungen nach Ganzkörperbestrahlung dargestellt.

Material und Methoden

Es erfolgte eine selektive Literaturrecherche über die Datenbank PubMed zur Radiotherapie von Leukämien und zu Ganzkörperbestrahlungen mit Fokus auf Nebenwirkungen sowie technische und konzeptionelle Neuerungen.

Ergebnisse

Die Ganzkörperbestrahlung ist eine effektive Therapie zur Konditionierung vor allogener Stammzelltransplantation und weist ein diverses, aber beherrschbares, Toxizitätsspektrum mit endokrinen, kardiopulmonalen, okulären, nephrologischen und neurologischen Langzeitnebenwirkungen sowie Sekundärneoplasien auf. Zusätzlich kann eine Radiotherapie in Niedrigdosis effektiv zur Behandlung myeloider Sarkome (Chlorome) angewendet werden.

Schlussfolgerung

Die Vielfalt der Nebenwirkungen nach Ganzkörperbestrahlung erfordert eine interdisziplinäre und langfristige Nachsorgebetreuung durch internistische Onkolog*innen/Transplantationsmediziner*innen und Radioonkolog*innen. Technische Entwicklungen der Strahlentherapie können in Zukunft eine selektive Adressierung des Knochenmarks sowie der lymphatischen Organe realisieren. Aktuell sind diese noch nicht in der klinischen Routine etabliert und werden im Rahmen klinischer Studien evaluiert.

Where do we stand with radioimmunotherapy for acute myeloid leukemia?

INTRODUCTION

Despite the approval of several new drugs, deaths from acute myeloid leukemia (AML) remain common. Because of well-defined cell surface antigens, easy accessibility, and radiosensitivity of leukemia cells, there is long-standing interest in radiolabeled antibodies (radioimmunotherapy [RIT]) to complement or replace existing treatments and improve outcomes in AML.

AREAS COVERED

Targeting primarily CD33, CD45, or CD66, early RIT efforts have focused on β-emitters, including iodine-131 (131I) and yttrium-90, mostly to intensify conditioning therapy before allogeneic hematopoietic cell transplantation (HCT). An 131I-labeled CD45 antibody (Iomab-B [apamistamab-I131]) is currently studied in the registration-type phase 3 SIERRA trial (NCT02665065) for this purpose. Of growing interest as therapeutic payloads are α-particle emitting radionuclides such as actinium-225 (225Ac) or astatine-211 (211At) since they deliver substantially higher decay energies over a much shorter distance than β-emitters, rendering them more suitable for precise, potent, and efficient target cell killing while minimizing toxicity to surrounding bystander cells, possibly allowing use outside of HCT. Clinical efforts with 211At-labeled CD45 antibodies and 225Ac-labeled CD33 antibodies (e.g. 225Ac-lintuzumab [Actimab-A]) are ongoing.

EXPERT OPINION

A first anti-AML RIT may soon become available. This might propel further work to develop RIT-based treatments for AML, with many such efforts already ongoing.

Single Fraction Radiation for Myeloid Sarcoma Is as Effective as Multi-Fraction Regimens for Tumor Regression and Control

INTRODUCTION/BACKGROUND

Myeloid sarcoma is a rare extramedullary manifestation of immature myeloid/monocyte cells. Radiotherapy (RT) yields good local control, but data on different fractionation schemes are limited. The goal of this retrospective study was to share our institutional experience and assess volumetric regression with differential fractionation.

MATERIALS AND METHODS

We evaluated patients treated for myeloid sarcoma between 2000 and 2019 and categorized them into Group A (treated with RT) and Group B (no RT). We assessed local control using cumulative incidence function analysis. Post-treatment imaging sequences were analyzed for volumetric calculations.

RESULTS

Forty-four patients with 80 lesions were assessed. Twenty-three patients with 52 lesions received RT (Group A), and 6 lesions received a single fraction of RT. There were 2 instances of local progression in Group A and 8 in Group B, with a cumulative incidence function estimate of local progression in Group A of 2.4% at 1 year and 6.9% at 2 years, significantly reduced compared to 29.7% and 35.5% in Group B, respectively (hazard ratio 0.13 [95% confidence interval 0.030.63], P = .011). No lesion treated with a single fraction of RT developed local progression. Volumetric analysis for 19 chronologically followed lesions (including 3 treated with a single fraction) revealed no difference in regression between single or multi-fraction treatment.

CONCLUSION

RT for myeloid sarcoma yields excellent local control and may be as effective in a single fraction as more protracted courses, though this requires validation. For a diagnosis associated with poor survival, a single palliative fraction may be optimal with potential for higher utilization.

Treatment of Extramedullary Myeloid Sarcoma With Radiotherapy

Myeloid sarcoma is a rare pathology with important clinical implications. In this paper, we report the case of a 95-year-old gentleman with an orbital mass, which was later confirmed to be a myeloid sarcoma. We also discuss the role of radiotherapy in regard to this diagnosis in patients.

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.

An Unusual Cause of Epistaxis: Paranasal Sinus Myeloid Sarcoma

We report a case of a 65-year-old female who presented with right-sided headaches, blurring of vision in the right eye, cold-induced epistaxis, and facial numbness in the trigeminal nerve distribution. Laboratory studies revealed a significant number of myeloblasts on peripheral smear with granulated cytoplasm, irregular nuclei, and prominent vacuoles. Magnetic resonance imaging (MRI) of the brain demonstrated a T1-enhancing 1.5 cm right-sided dural-based lesion involving the medial sphenoid wing, cavernous sinus, infratemporal fossa, and sphenoid sinus region. An endoscopic biopsy of the lesion within the sphenoid sinus confirmed the diagnosis of myeloid sarcoma, with myeloblasts comprising 30% of cellularity by flow cytometry. A subsequent bone marrow biopsy revealed a hypercellular marrow with 23% blasts by flow cytometry that demonstrated a similar immunophenotypic pattern to those seen in the sinus mass. Fluorescence in situ hybridization (FISH) testing revealed the balanced translocation t(8;21)(q22;q22.1), consistent with a diagnosis of acute myeloid leukemia with RUNX1-RUNX1T1-balanced translocation by WHO 2016 criteria. Myeloid sarcoma represents a rare extramedullary presentation of acute myeloid leukemia (AML), either alone or in conjunction with blood or bone marrow involvement. This case emphasizes the need for a broad differential diagnosis and an aggressive work-up for any unusual paranasal sinus mass.

Use of Radiation in Extramedullary Leukemia/Chloroma: Guidelines From the International Lymphoma Radiation Oncology Group

Survival times for patients with leukemia generally have improved in recent decades, and this improvement has been attributed to an enhanced understanding of the genetics driving the cause of the disease and improved combinations of chemotherapy and targeted therapy. Durable control of systemic disease in blood and bone marrow has significantly improved survival, but extramedullary relapse can pose therapeutic challenges for which radiation therapy can have an important role. This report discusses the current role of radiation therapy for patients with leukemia, specifically the extramedullary manifestations of leukemia.

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.

Myeloid sarcoma of the periprostatic tissue and prostate: Case report and review of literature

Myeloid sarcoma (MS) is a rare extramedullary tumor composed of immature cells of myeloid lineage that destroy the original tissue architecture in which it is found. It is most commonly identified in patients with acute myelogenous leukemia, and less often in myelodysplastic syndromes (MDSs) and other myeloproliferative disorders. It is most commonly reported in the periosteum, bone, skin, and lymph nodes but has been reported in many other sites of the body. Herein, we describe a case of MS involving the periprostatic tissue and review of literature of MS of the prostate. Our patient was initially diagnosed with MDS and was in remission following successful treatment. Six months later, the patient was diagnosed with prostate adenocarcinoma, and MS of the periprostatic tissue was incidentally discovered in the postprostatectomy pathology specimen. An extensive review of literature from 1997 to 2014 revealed a total of eight cases of MS involving the prostate. Of the eight cases of MS of the prostate, four were primary MS (absence of a history of leukemia) and four were secondary MS. Three received local radiation to the prostate with relief of obstructive symptoms, and one of them had a repeat prostate biopsy negative for leukemic cells. Despite being a rare entity, MS should be considered as a differential diagnosis of soft tissue masses, especially in patients with a history of hematological malignancies.

[Radiotherapy of chloroma or granulocytic sarcoma: A literature review]

Granulocytic sarcoma, or chloroma, is a rare clinical entity, usually associated with a blood disease, including acute myeloid leukemia. Management strategies are based on the combination of systemic therapy and local therapy (surgery or radiation). Data for radiotherapy dose are derived from retrospective studies and case reports. We conducted a literature review using the Pubmed search engine to clarify the terms and indications for radiotherapy of chloromas.

Radiotherapy for granulocytic sarcoma of the breast-Case report and review of the literature

Granulocytic sarcomas are rare tumors that can present in innumerous locations; thus there is very little clinical experience with these cases. Therefore there is no consensus on which is the best treatment for patients with this malignancy. The authors present a case of a female with a granulocytic sarcoma of the breast and review the literature for the role of radiotherapy in the management of this clinical entity.

A collimated detection system for assessing leakage dose from medical linear accelerators at the patient plane

Leakage radiation from linear accelerators can make a significant contribution to healthy tissue dose in patients undergoing radiotherapy. In this work thermoluminescent dosimeters (LiF:Mg,Cu,P TLD chips) were used in a focused lead cone loaded with TLD chips for the purpose of evaluating leakage dose at the patient plane. By placing the TLDs at one end of a stereotactic cone, a focused measurement device is created; this was tested both in and out of the primary beam of a Varian 21-iX linac using 6 MV photons. Acrylic build up material of 1.2 cm thickness was used inside the cone and measurements made with either one or three TLD chips at a given distance from the target. Comparing the readings of three dosimeters in one plane inside the cone offered information regarding the orientation of the cone relative to a radiation source. Measurements in the patient plane with the linac gantry at various angles demonstrated that leakage dose was approximately 0.01% of the primary beam out of field when the cone was pointed directly towards the target and 0.0025% elsewhere (due to scatter within the gantry). No specific 'hot spots' (e.g., insufficient shielding or gaps at abutments) were observed. Focused cone measurements facilitate leakage dose measurements from the linac head directly at the patient plane and allow one to infer the fraction of leakage due to 'direct' photons (along the ray-path from the bremsstrahlung target) and that due to scattered photons.

Clinicopathologic features and responses to radiotherapy of myeloid sarcoma

Background

To evaluate clinicopathological features, radiotherapeutic parameters, and their associations with responses to radiotherapy (RT) in patients with myeloid sarcoma (MS).

Methods

We reviewed 20 patients receiving RT for MS lesions (in 43 RT courses) and analyzed the patients’ clinicopathologic features and radiotherapeutic parameters, and their associations with complete responses (CR) to RT using Fisher’s exact test and univariate logistic regression analysis. Generalized Estimating Equation was used to analyze all 43 irradiated lesions and account for the correlations in RT responses among lesions from the same patient.

Results

We found that the underlying hematological diseases of the evaluated patients were acute myeloid leukemia (AML) in 14 patients (70%), chronic myeloid leukemia in 4 patients (20%), myelodysplastic syndrome with AML transformation in one patient (5%), and de novo MS in one patient (5%). Most patients (55%) received RT for MS at the time of relapse following bone marrow transplantation (BMT). The most common cytogenetic abnormality was t(8;21)(q22;q22). The median RT dose of 20 Gy (range 6–35 Gy), administered in 1.5-3.5 Gy fractions, provided a 63% CR rate. RT dose, sex, cytogenetics, and bone marrow status at the time of RT had no significant effect on CR. Younger age (<50 y, P = 0.06), BMT prior to RT (P = 0.05), and underlying AML (P = 0.05) were marginally associated with higher CR to RT.

Conclusions

Our results indicate that a modest RT dose (20-30 Gy) achieves good local control of MS. Age, previous BMT, and underlying hematologic disease can affect RT response.

Myeloid sarcoma of the nasopharynx mimicking an aggressive lymphoma

BACKGROUND

Myeloid sarcoma (MS) is a rare extra-medullary tumour of the myeloid lineage, which can be a difficult diagnosis to make.

CASE PRESENTATION

We report the case of a 73-year-old male with a right-sided nasopharyngeal mass revealed on CT scan and MRI.

RESULTS

An initial cytological and histological examination suggested a high-grade lymphoma. Nevertheless, the final diagnosis was a MS with an unusual involvement of the nasopharynx that was treated with a conventional induction leukemia therapy. Eight months later, the patient had persistent thrombocytopenia and a bone marrow aspiration showed the dysplasia of a high grade myelodysplastic syndrome and cytogenetics detected t(3;21). The patient was treated with a 5-Azacitidine (Vidaza) protocol until overt progression and disease evolution.

CONCLUSION

In conclusion few cases of MS involving the nasopharynx have been reported. Its diagnosis is often difficult and should be considered especially when a high index of suspicion is present and the immunophenotype of the malignant haematological cells is not clearly in favour of a lymphoma.

Radiation therapy for chloroma (granulocytic sarcoma)

OBJECTIVES

Chloroma (granulocytic sarcoma) is a rare, extramedullary tumor of immature myeloid cells related to acute nonlymphocytic leukemia or myelodysplastic syndrome. Radiation therapy (RT) is often used in the treatment of chloromas; however, modern studies of RT are lacking. We reviewed our experience to analyze treatment response, disease control, and toxicity associated with RT to develop treatment algorithm recommendations for patients with chloroma.

PATIENTS AND METHODS

Thirty-eight patients who underwent treatment for chloromas at our institution between February 1990 and June 2010 were identified and their medical records were reviewed and analyzed.

RESULTS

The majority of patients that presented with chloroma at the time of initial leukemia diagnosis (78%) have not received RT because it regressed after initial chemotherapy. Yet most patients that relapsed or remained with chloroma after chemotherapy are in the RT cohort (90%). Thirty-three courses of RT were administered to 22 patients. Radiation subsite breakdown was: 39% head and neck, 24% extremity, 9% spine, 9% brain, 6% genitourinary, 6% breast, 3% pelvis, and 3% genitourinary. Median dose was 20 (6-36) Gy. Kaplan-Meier estimates of progression-free survival and overall survival in the RT cohort were 39% and 43%, respectively, at 5 years. At a median follow-up of 11 months since RT, only 1 patient developed progressive disease at the irradiated site and 4 patients developed chloromas at other sites. RT was well tolerated without significant acute or late effects and provided symptom relief in 95% of cases.

CONCLUSIONS

The majority of patients with chloromas were referred for RT when there was extramedullary progression, marrow relapse, or rapid symptom relief required. RT resulted in excellent local disease control and palliation of symptoms without significant toxicity. We recommend irradiating chloromas to at least 20 Gy, and propose 24 Gy in 12 fractions as an appropriate regimen.

How I treat extramedullary acute myeloid leukemia

Extramedullary (EM) manifestations of acute leukemia include a wide variety of clinically significant phenomena that often pose therapeutic dilemmas. Myeloid sarcoma (MS) and leukemia cutis (LC) represent 2 well-known EM manifestations with a range of clinical presentations. MS (also known as granulocytic sarcoma or chloroma) is a rare EM tumor of immature myeloid cells. LC specifically refers to the infiltration of the epidermis, dermis, or subcutis by neoplastic leukocytes (leukemia cells), resulting in clinically identifiable cutaneous lesions. The molecular mechanisms underlying EM involvement are not well defined, but recent immunophenotyping, cytogenetic, and molecular analysis are beginning to provide some understanding. Certain cytogenetic abnormalities are associated with increased risk of EM involvement, potentially through altering tissue-homing pathways. The prognostic significance of EM involvement is not fully understood. Therefore, it has been difficult to define the optimal treatment of patients with MS or LC. The timing of EM development at presentation versus relapse, involvement of the marrow, and AML risk classification help to determine our approach to treatment of EM disease.

Recurrent neurotropic chloroma: report of a case and review of the literature

We are reporting a case of a young woman with acute myelogenous leukemia status postallogeneic transplantation who developed multiply recurrent chloromas occurring along peripheral nerves in the absence of bone marrow relapse, all treated with radiation therapy. The patient is currently free of disease nearly four years after her first posttransplant chloroma. The case presented is unique for its isolated peripheral nervous system involvement, rare posttransplant occurrence, and indolent course without marrow relapse despite multiple extramedullary recurrences.

A review of dosimetry studies on external-beam radiation treatment with respect to second cancer induction

It has been long known that patients treated with ionizing radiation carry a risk of developing a second cancer in their lifetimes. Factors contributing to the recently renewed concern about the second cancer include improved cancer survival rate, younger patient population as well as emerging treatment modalities such as intensity-modulated radiation treatment (IMRT) and proton therapy that can potentially elevate secondary exposures to healthy tissues distant from the target volume. In the past 30 years, external-beam treatment technologies have evolved significantly, and a large amount of data exist but appear to be difficult to comprehend and compare. This review article aims to provide readers with an understanding of the principles and methods related to scattered doses in radiation therapy by summarizing a large collection of dosimetry and clinical studies. Basic concepts and terminology are introduced at the beginning. That is followed by a comprehensive review of dosimetry studies for external-beam treatment modalities including classical radiation therapy, 3D-conformal x-ray therapy, intensity-modulated x-ray therapy (IMRT and tomotherapy) and proton therapy. Selected clinical data on second cancer induction among radiotherapy patients are also covered. Problems in past studies and controversial issues are discussed. The needs for future studies are presented at the end.

Prostatic extramedullary leukemia as a first site of relapse of acute nonlymphocytic leukemia

Extramedullary leukemia (EML) is an uncommon clinical diagnosis in patients with acute nonlymphocytic leukemia (ANLL). Prostatic EML as a first site of ANLL relapse is even more rare. To our knowledge, only three cases have been reported. We describe an additional case of prostatic EML as a site of ANLL relapse. An asymptomatic male in ANLL remission was found to have a normal prostate-specific antigen (PSA) and a myeloid leukemic infiltrate in a newly diagnosed prostate nodule. Staging was negative for ANLL relapse. Local prostate radiation resolved the nodule, and the post-treatment needle biopsies were negative. He subsequently developed clinical relapse in bone marrow, blood, and small bowel and received salvage chemotherapy with mitoxantrone and etoposide.

Granulocytic sarcoma: an unusual complication of aleukemic myeloid leukemia causing spinal cord compression. A case report and literature review

Granulocytic sarcoma (chloroma) is a rare solid tumor resulting from the proliferation of myelogenous leukemia cells. Chloromas usually present as soft tissue or bony masses of the head and neck in patients with acute myelogenous leukemia (AML) of the French-American-British M2 subtype. Occasionally chloromas may occur in patients with myelodysplasia and other myeloproliferative disorders and rarely precede the development of systemic disease. It is distinctly rare for such tumors to cause epidural compression as a first manifestation of disease. Herein, we report the case of a man with a thoracic extradural chloroma whose presentation of progressive lumbar pain ultimately led to the diagnosis of M2 AML. Surgical intervention prior to the onset of paraplegia and the prompt initiation of chemotherapy resulted in an excellent neurological and hematological outcome. We also review the literature of previously reported cases of spinal cord-associated chloroma and focus on the clinical presentation and treatment of this disorder.

Extramedullary leukemia in children with newly diagnosed acute myeloid leukemia: a report from the Children's Cancer Group

OBJECTIVES

To describe features of patients with acute myeloid leukemia presenting with extramedullary leukemic tumors (EML).

METHODS

Among 1,832 patients entered on Children's Cancer Group's chemotherapy trials with acute myeloid leukemia, 199 patients had EML, defined as any leukemic collection outside the bone marrow cavity. Three patient groups were denoted: group 1 (n=109) with EML involving skin (with or without other sites of EML), group 2 (n=90) with EML in sites other than skin, and group 3 (n=1,633) without EML.

RESULTS

The incidence of EML was 10.9%. Group 1 patients tended to be younger, had higher white blood cell counts, were more often CNS positive, had FAB M4 or M5 subtypes, and possessed more abnormalities of chromosome 11 than group 3 patients. Group 2 patients were younger, more often had the FAB M2 subtype, and had a higher incidence of t(8;21)(q22;q22) abnormality than group 3, but had similar white blood cell counts and incidence of CNS positivity at diagnosis. For group 1 the 5-year event-free survival was 26%, significantly worse than for group 3 at 29%. Event-free survival was better for group 2 patients (5-year estimate 46%), which remained a favorable prognostic factor by multivariate analysis. The authors retrospectively determined whether 118 (59%) of the EML patients received localized radiotherapy to the site of EML: 42 did and 76 did not. There were no differences in estimated event-free survival between patients who did and did not receive radiotherapy.

CONCLUSIONS

Non-skin (group 2) EML appeared to be an independent favorable prognostic factor. Localized radiotherapy to the site of EML at the end of induction chemotherapy did not improve outcome.

Presentation of M4 acute myeloid leukemia in anuric renal failure with hyperuricemia and enlarged kidneys

Extramedullary acute myeloid leukemia (AML) is not uncommon. It has been shown to involve the kidneys in most postmortem cases but is most often clinically insignificant. By contrast, acute tumor lysis syndrome is rare in AML, especially at initial diagnosis. The authors report the management of a patient with AML who had acute tumor lysis syndrome that was probably potentiated by renal leukemia and resulted in renal failure. This patient achieved remission with dose-modified induction chemotherapy administered while he was dialysis-dependent.

Isolated granulocytic sarcoma of the skin in an elderly patient: good response to treatment with local radiotherapy and low-dose methotrexate

Granulocytic sarcoma of the skin is frequently associated with haematological diseases and is rarely isolated. The disease generally develops into acute systemic myeloid leukaemia and is associated with a poor prognosis. We report an elderly patient presenting isolated granulocytic sarcoma of the skin who showed a very good response to treatment with local radiotherapy and low-dose methotrexate.

Extramedullary myeloid tumors in children: the limited value of local treatment

PURPOSE

To determine the incidence of extramedullary tumors (EMT) in Saudi Arabian children with acute myeloid leukemia, the factors associated with these tumors and the impact of local treatment on local tumor control, complete remission and survival rates.

PATIENTS AND METHODS

One hundred children, median age 6 years, who received their primary treatment for acute myeloid leukemia at King Faisal Specialist Hospital and Research Center, from 1983 to 1997 were studied. EMT at diagnosis occurred in 18 (18%) patients at 25 sites. Meningeal leukemia, hepatosplenomegaly, lymph node enlargement, gingival hypertrophy, and cutaneous infiltration were not included in the definition of EMT. With these exclusions, children with EMT were younger than those without EMT (median age, 3.5 v. 7.5 years) and were more likely to have meningeal leukemia at diagnosis (33% v. 10%). The t(8;21) translocation was associated with a 47% EMT incidence compared with 23% without the translocation. Local radiation treatment was given to 16 of 25 (64%) EMT sites.

RESULTS

The overall 5-year survival rate for all patients was 28%, and this was not significantly influenced by the drug regimen used, meningeal leukemia at diagnosis, the presence of the (8;21) translocation, M4 and M5 morphology combined, or EMT at diagnosis. Significant differences were observed in the 5-year survival rates for patients who underwent allogeneic bone marrow transplantation (52%; N = 37) and those who attained complete remission (CR) but did not undergo transplantation (21%; N = 44) and those who did not achieve complete remission with initial therapy (5%; N = 19). Systemic and local EMT CR was achieved in 17 of 18 patients with EMT, including 12 patients who underwent radiation treatment and 5 of 6 of those who did not. Isolated relapse was not seen at an EMT site and was not noted at any later stage of the disease.

CONCLUSIONS

Permanent local control at sites of EMT was achieved in all patients who attained a bone marrow CR, whether or not the site was irradiated. Local radiation treatment of an EMT site did not appear to contribute to overall CR and survival rates. The use of radiation treatment should be conservative and limited to patients in whom there is a real and immediate threat to vision or renal function or when the spinal cord is compromised.

[Radiotherapy in leukemia excluding total body irradiation]

Radiation techniques and indications in leukemias have been described in detail, yet prophylactic cranial irradiation in acute leukemia still has few indications. Cerebrospinal and testicular irradiation are reserved for relapsing disease. Radiation usually results in rapid functional improvement when used in neurologic emergencies and symptomatic neurologic or gross tumors relapses. Nevertheless, the improvements recently obtained by systemic chemotherapy have resulted in the reduction in the use of irradiation, especially in children, where it was considered deleterious with neuropsychological sequellae. Splenic irradiation remains useful for symptomatic myeloproliferative syndrome.

Extramedullary tumors of myeloid blasts in adults as a pattern of relapse following allogeneic bone marrow transplantation

BACKGROUND

Extramedullary tumors of lymphoid and myeloid blasts outside the well-defined sanctuaries following allogeneic bone marrow transplantation (allo-BMT) are rare. Little is known about the biology, treatment, and outcome of these tumors in this setting.

METHODS

In this retrospective analysis, 134 consecutive patients with acute myeloid leukemia (AML) or chronic myeloid leukemia (CML) who underwent allo-BMT at a single institution between 1990 and 1998 were reviewed. Five cases of isolated extramedullary myeloid sarcoma that occurred as patterns of recurrence following allo-BMT between 1990 and 1998 are reported. These patients were treated with radiotherapy, systemic chemotherapy, or a second allo-BMT. Clinical outcome is compared with posttransplantation bone marrow relapses observed during the same period at the same institution. The literature on the clinical characteristics, currently available treatment, and outcome of posttransplantation myeloid sarcoma patients was reviewed.

RESULTS

Excluding isolated skin and central nervous system recurrences, the frequency of extramedullary myeloid sarcoma encountered as a relapse pattern following allo-BMT was determined to be 3.7% among patients with acute or chronic leukemia of myeloid origin. The survival of patients who were managed with radiotherapy and systemic chemotherapy was less than 4 months. A patient who underwent a second allo-BMT following local radiotherapy is alive and in complete remission more than 33 months after the diagnosis of myeloid sarcoma. The median survival of 17 patients with posttransplantation bone marrow relapse following allo-BMT was 2.2 months. When posttransplantation medullary recurrences are analyzed, patients with CML had a median survival of 12 months, with a significantly better 5-year survival rate than patients with AML (0 vs. 60%, P = 0.015; median survival, 12 months).

CONCLUSIONS

The clinical outcomes of patients with recurrent isolated extramedullary myeloid sarcoma following allo-BMT are poor, as in any leukemic relapse, with the exception of patients with CML in this setting.

Gamma-irradiation does not impair ATRA-induced maturation of myeloid leukaemic cells: implication for combined radiation and differentiation therapy

In the present study we investigated the effects of various doses of gamma-irradiation, followed by induction of granulocytic differentiation with all-trans-retinoic acid (ATRA), on proliferative rate, differentiation capability and oxidative metabolism of leukaemic cells from two different myeloid leukaemia cell lines, HL-60 and PLB-985. Regarding the effects of such combined treatment on the proliferative capabilities of HL-60 and PLB-985 cell lines, we showed that their growth kinetics were similar after 2 Gy gamma-irradiation combined with ATRA. However, with doses >2 Gy, the behaviour of the cell lines differed largely. Indeed, HL-60 appeared to be more radiosensitive than PLB-985 regarding cell viability and proliferation. Besides, whatever dose of irradiation (2, 5 or 10 Gy) was applied, ATRA was still able to induce differentiation of HL-60 and PLB-985 into granulocytes that retained the capacity to produce superoxide anion. The results of these in vitro studies suggest that leukaemia cell lines retain their ability to respond to ATRA, a granulocytic-differentiating inducer following high doses of irradiation. This may have implications for the use of radiation therapy in combination with ATRA for the treatment of extramedullary infiltrations of myeloid leukaemias in humans.

Donor leukocyte transfusions for treatment of leukemic relapse after bone marrow transplantation. EBMT Immunology and Chronic Leukemia Working Parties

Allogeneic bone marrow transplantation is an effective treatment of leukemia. Intensive chemo- and radiotherapy used for conditioning and T-cells of the graft contribute to the control of leukemia. Animal experiments indicate that transfusion of lymphocytes from the marrow donor convert into complete chimerism without producing graft-versus-host disease, if delayed for two months or more. Transfusion of donor leukocytes (DLT) after marrow transplantation has induced lasting remissions in the majority of patients with chronic myelogenous leukemia (CML) in hematological or cytogenetic relapse, some patients with acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), transformed phase CML and multiple myeloma (MMY). The mechanism of the graft-versus-leukemia reaction is discussed.

Primary extramedullary leukemia of the prostate: case report and review of the literature

We present the case of a 67-year-old male with primary extramedullary leukemia of the prostate gland, the first reported case in the literature to the best of our knowledge. His initial symptoms consisted of episodes of urinary retention. He underwent transurethral resection of the prostate, and a diagnosis of high-grade lymphoma was rendered. He then received a course of doxorubicin-based lymphoma chemotherapy regimen. However, based on a panel of immunocytochemical stains, a diagnosis of extramedullary leukemia or chloroma was confirmed. His bone-marrow examination at this point was normal. He underwent radiation therapy to the prostate with a total dose of 3960 cGy. Seven months after his initial presentation, he progressed to acute nonlymphocytic leukemia (ANLL), M2 by FAB classification. He was successfully treated with induction and consolidation chemotherapy with Ara-C and idarubicin, and was maintained in complete remission up to 19 months of follow-up. Eight other cases of prostatic leukemia reported in the literature are presented. Five cases occurred in association with ANLL, 2 cases as sites of ANLL relapse, and 1 case in association with myelodysplasia. The use of immunohistochemical stains has aided us in diagnosis of extramedullary leukemia. Surgery, radiation therapy, and chemotherapy play complementary roles in the treatment of prostatic extramedullary leukemia.

Testicular relapse in children with acute nonlymphoblastic leukemia

The clinical course and other distinctive features of five children who developed a testicular relapse 4 months to 25 months after the diagnosis of acute nonlymphoblastic leukemia (ANLL) are described. The chief presenting feature at relapse was painless testicular enlargement, as is also seen in children with acute lymphoblastic leukemia who relapse in the testes. By French-American-British convention, the malignant cells were classified as M4 (myelomonoblastic) in four cases and M2 (myeloblastic) in one. All children received a course of multiagent reinduction chemotherapy and all but one received local irradiation to the testes. Only one of these children, whose relapse was a late event after elective cessation of therapy, is a long-term survivor. A comparison with six previously published cases shows similar clinical characteristics and outcome. Given the poor responses of such patients to conventional treatment, it seems worthwhile to consider the use of intensive reinduction chemotherapy with concomitant bilateral testicular irradiation followed by remission intensification and an autologous or allogenic marrow transplant.

Dose rate and fractionation of total body irradiation in dogs: short and long term effects

Variations of regimens of total body irradiation (TBI) were investigated in the dog as a preclinical model for bone marrow transplantation. Inactivation of hemopoietic precursor cells (CFU-GM) was studied following irradiation of marrow in vitro, following TBI at sublethal doses in vivo and following autologous transplantation of marrow obtained after sublethal TBI. Inactivation and recovery of CFU-GM as well as restoration of hemopoiesis following autologous transplantation was independent of the dose rate, but nadirs of blood counts were lower following sublethal TBI with the higher dose rate. Acute non-hemopoietic toxicity of TBI depended on the dose, the dose rate and the total treatment time and not on the fractionation regimen. At a total dose of 25 Gy acute mortality was prevented by prophylactic administration of oral, non-absorbable antibiotics. Late mortality was due to degenerative and autoimmune-like disorders with or without infections and to malignant tumors. Evaluation of long-term survival is still preliminary, since surviving dogs of two groups (10 Gy as single dose, 25 Gy as hyperfractionated TBI) have not yet reached the median survival time of their group. So far, long-term survival depended on the total dose (p = 0.05) and, possibly, the fractionation regimen (p = 0.12). The latency period until development of malignant tumors was influenced by the total doses given in the same treatment time (p = 0.05) and by the total treatment time for equal doses (p = 0.04). It was concluded that TBI at a low dose rate may give the best therapeutic ratio of inactivation of hemopoietic precursor cells to acute toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Granulocytic sarcoma of the prostate. Two cases causing urinary obstruction

Two cases of patients with prostatic granulocytic sarcoma in whom urinary obstruction occurred are presented. The diagnosis was made by tissue examination with hematoxylin and eosin and specific esterase stains. One patient had a myelodysplastic syndrome and the other patient had acute myeloblastic leukemia. In both cases the diagnosis of prostatic granulocytic sarcoma was unexpected. Granulocytic sarcomas should be considered in the differential diagnosis of urinary obstruction in patients with myeloproliferative or myelodysplastic syndromes.