Myeloid sarcomas: a histologic, immunohistochemical, and cytogenetic study

Isolated myeloid sarcoma of the tibia: A case report

INTRODUCTION

Myeloid sarcoma (MS) is a rare extramedullary tumor composed of malignant myeloid cells that most commonly arise in patients previously diagnosed with myeloproliferative disease. However, they can still occur in isolation and without bone marrow disease.

CASE PRESENTATION

An 8-year-old girl who had a history of acute myeloid leukemia and was off treatment for four years presented to the clinic with a history of on and off left knee swelling and pain without any direct trauma to the knee over the last two years. Knee Magnetic resonance imaging (MRI) showed diffused joint effusion with proximal tibia focal edema. A diagnosis of juvenile rheumatoid arthritis was suspected, and the patient was started on treatment, but the problem did not resolve. Eventually, the patient underwent a repeat MRI and showed increased joint effusion with an increase in the focal edema. An open bone biopsy of the lesion was taken, and the histopathology showed sheets of primitive mononuclear cells positive for CD33 and CD117 and negative for CD34, myeloperoxidase, CD10, CD20, and CD68, indicating myeloid sarcoma.

CLINICAL DISCUSSION

Histological examination and immunohistochemistry are the most important in diagnosing myeloid sarcoma. Previously, before the introduction of chemotherapy and stem cell transplant, such cases of proximal tibia MS were treated with surgical resection of the bone. However, chemotherapy with the possibility of an allogeneic hematopoietic stem cell transplant (alloHSCT) has changed the view of survival in such cases.

CONCLUSION

Isolated proximal tibia myeloid sarcoma is a rare occurrence that can be misdiagnosed and lead to delayed treatment. Bone biopsy, Immunohistochemistry, and cytogenetic studies play a critical role in differentiating MS from other types of tumors.

Diagnostic Challenges of Aleukemic Myeloid Sarcoma

Myeloid sarcoma (MS) represents a neoplastic proliferation characterized by immature myeloid precursor cells. Among its variants, aleukemic MS is an uncommon subtype, manifesting as skin involvement sparing the peripheral blood or bone marrow. The non-specific cutaneous presentation coupled with the lack of associated symptoms poses a diagnostic challenge for providers. In this report, we present a case of an 83-year-old woman who presented with violaceous nodules located in the center of her right shin. A biopsy of the lesion unveiled a diagnosis of MS, yet notably lacked peripheral blood involvement. Three months after the initial diagnosis, the MS was found in the common bile duct, still without bone marrow involvement. With a relatively poor prognosis, the rapid diagnosis and treatment of MS are crucial.

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.

The immutable relevance of myeloid sarcomas: Clinicopathological study of fourteen cases

An extramedullary myeloid tumor or chloroma is an infrequent manifestation of a myeloid neoplasm. It is considered an equivalent to an acute myeloid leukemia. It is confirmed through biopsy, where infiltrating neoplastic myeloid cells distort the parenchyma. A total of twenty-nine cases were diagnosed as MS between 198 and 2023. Upon re-evaluation, only fourteen cases fulfilled the criteria for MS. The most common differential diagnosis were lymphomas, leukemic infiltration, and extramedullary hematopoiesis. Few were isolated cases; the rest were in the context of progression of a myeloid neoplasm. The majority had a myelomonocytic morphology and immunophenotype. The most reliable markers were CD45, HLA-DR, CD68 and CD4. The study highlights the complexity and impact of an accurate diagnosis of a myeloid sarcoma.

Cutaneous Manifestations of Myeloid Neoplasms Exhibit Broad and Divergent Morphologic and Immunophenotypic Features but Share Ancestral Clonal Mutations With Bone Marrow

In this study, we performed a comprehensive molecular analysis of paired skin and peripheral blood/bone marrow (BM) samples from 17 patients with cutaneous myeloid or cutaneous histiocytic-dendritic neoplasms. The cutaneous manifestations included 10 patients with cutaneous acute myeloid leukemia (c-AML), 2 patients with full or partial Langerhans cell differentiation, 2 patients with blastic plasmacytoid dendritic cell neoplasms (BPDCN), 1 patient with both Langerhans cell differentiation and BPDCN, and 2 patients with full or partial indeterminate dendritic cell differentiation. Seven of the 10 c-AML patients (70%) exhibited concurrent or subsequent marrow involvement by acute myeloid leukemia, with all 7 cases (100%) demonstrating shared clonal mutations in both the skin and BM. However, clonal relatedness was documented in one additional case that never had any BM involvement. Nevertheless, NPM1 mutations were identified in 7 of the 10 (70%) of these c-AML cases while one had KMT2A rearrangement and one showed inv(16). All 3 patients (100%) with Langerhans cell neoplasms, 2 patients with BPDCN (100%), and one of the 2 patients (50%) with other cutaneous dendritic cell neoplasms also demonstrated shared mutations between the skin and concurrent or subsequent myeloid neoplasms. Both BM and c-AML shared identical founding drivers, with a predominance of NPM1, DNMT3A, and translocations associated with monocytic differentiation, with common cutaneous-only mutations involving genes in the signal transduction and epigenetic pathways. Cutaneous histiocytic-dendritic neoplasms shared founding drivers in ASXL1, TET2, and/or SRSF2. However, in the Langerhans cell histiocytosis or histiocytic sarcoma cases, there exist recurrent secondary RAS pathway hits, whereas cutaneous BPDCN cases exhibit copy number or structural variants. These results enrich and broaden our understanding of clonally related cutaneous manifestations of myeloid neoplasms and further illuminate the highly diverse spectrum of morphologic and immunophenotypic features they exhibit.

Dysphagia as an Initial Presentation of Acute Myeloid Leukemia: A Rare Presentation of Myeloid Sarcoma

Myeloid sarcoma (MS) represents a unique clinical presentation of acute myeloid leukemia (AML). This report describes a case of MS in a 66-year-old man who presented with dysphagia, nausea, vomiting, anorexia, and fatigue. Generalized lymphadenopathy was noted on physical exam and confirmed by CT scans which also showed diffuse esophageal wall thickening. Axillary lymph node biopsy was positive for MS. Bone marrow biopsy confirmed AML with 88% blasts. The patient received induction chemotherapy with decitabine and venetoclax and was planned for four cycles of treatment over three months while monitoring the response.

Multimodal imaging study of pancreatic myeloid sarcoma: a case report and literature review

Myeloid sarcoma (MS) is a rare extramedullary parenchymal tumor composed of immature myeloid cells, occurring mainly in the lymph nodes, skin, soft tissue, testicles, bones, peritoneum, and gastrointestinal tract, and rarely in the pancreas. Herein, we report the case of a 68-year-old female patient who visited our hospital for medical assistance due to acute abdominal pain. Abdominal computed tomography (CT) and magnetic resonance imaging showed a mass approximately 8 cm in diameter in the pancreatic tail, which was suspected to be a malignant tumor. To further assess the presence of distant metastases, the patient underwent fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT, which revealed an increased 18F-FDG uptake in the corresponding lesions. Subsequently, the patient underwent surgical treatment, and postoperative pathology and immunohistochemistry revealed that the mass was MS. Moreover, we reviewed the clinical features, imaging findings, and histopathology of pathologically confirmed pancreatic MS in the published literature.

Skin Involvement by Hematological Neoplasms with Blastic Morphology: Lymphoblastic Lymphoma, Blastoid Variant of Mantle Cell Lymphoma and Differential Diagnoses

Hematological neoplasms sharing a blastic morphology may involve the skin. The skin may be either the primary site of occurrence of hematological malignancies with blastic features or cutaneous lesions are the first manifestation of an underlying systemic malignancy. The assessment of skin biopsies of hematological neoplasms with blastic features poses diagnostic problems and requires expert hematopathologists considering a wide range of differential diagnoses. The precise diagnosis of diseases sharing blastic features but with different outcomes and requiring distinct therapies is essential for patient management. The present paper mainly focuses on cutaneous involvement of the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma of B-cell or T-cell origin. The relevant literature has been reviewed and the clinical aspects, pathological features, prognosis, and therapy of both blastoid mantle cell lymphoma and lymphoblastic lymphoma involving the skin are discussed. A focus on other hematological entities with blastic features, which may involve the skin, to be taken into consideration in differential diagnosis is also given.

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.

Exome sequencing analysis of gastric primary myeloid sarcoma with monocytic differentiation with altered immunophenotype after chemotherapy: case report

BACKGROUND

Myeloid Sarcoma with monocytic differentiation is rare and quite likely is missed by surgical pathologists. However it is frequently misdiagnosed because of its non-specific imaging and histological pattern.

CASE PRESENTATION

We report the case of a 64-year-old woman with gastric primary myeloid sarcoma with monocytic differentiatio. Upper endoscopy revealed a neoplastic growth at the junction of the lesser curvature and gastric antrum. Except for a slightly increased peripheral monocyte count, no abnormalities were found on hematological and bone-marrow examination. Gastroscopic biopsy showed poorly differentiated atypical large cells with visible nucleoli and nuclear fission. Immunohistochemistry showed positive CD34, CD4, CD43, and CD56 expression, and weakly positive lysozyme expression. Immune markers for poorly differentiated adenocarcinoma, malignant melanoma, and lymphohematopoietic-system tumors were negative. The final diagnosis was myeloid sarcoma with monocytic differentiation. Chemotherapy did not shrink the tumor, so, radical surgery was performed. Although the tumor morphology did not change postoperatively, the immunophenotype did. CD68 and lysozyme expression (tumor tissue markers) changed from negative and weakly positive to strongly positive, AE1/3 expression (epithelial marker) changed from negative to positive, and CD34, CD4, CD43, and CD56 expression (common in naive hematopoietic cell-derived tumors) was greatly attenuated. Exome sequencing revealed missense mutations in FLT3 and PTPRB, which are associated with myeloid sarcoma, and in TP53, CD44, CD19, LTK, NOTCH2, and CNTN2, which are associated with lymphohematopoietic tumors and poorly differentiated cancers.

CONCLUSION

We diagnosed myeloid sarcoma with monocytic differentiation after excluding poorly differentiated adenocarcinoma, common lymphohematopoietic-system tumors, epithelioid sarcoma, and malignant melanoma. We identified that the immunophenotypic of patient had alterations after chemotherapy, and FLT3 gene mutations. We hope that the above results will improve our understanding of this rare tumor.

Acute Myeloid Leukemia in a Cholecystectomy Specimen

A 76-year-old man was admitted into the ER for upper abdominal pain. Physical exam and CT scan confirmed acute cholecystitis with multiple cholelithis, and a cholecystectomy was performed. The cholecystectomy specimen showed chronic cholecystitis with exuberant inflammatory infiltrate. On careful examination of the specimen, large atypical cells with vesicular chromatin, folded nuclei, and inconspicuous red nucleoli were noted percolating into the gallbladder wall and lining vascular spaces. These cells were positive for CD117, CD43, and myeloperoxidase and negative for CD20 and CD3 stains. Further workup including peripheral blood flow cytometry confirmed a population of circulating immature myeloid precursors comprising about 38% of events. This is a rare case of acute myeloid leukemia that came to clinical attention by incidentally involving the gallbladder.

Myeloid sarcoma of the skull base: A case report and systematic literature review

Background:

Myeloid sarcoma (MS), or chloroma, is a rare extramedullary malignant tumor that consists of undifferentiated granulocytic cells, and it is most commonly associated with acute myeloid leukemia (AML). Intracranial MS accounts for 0.4% of MS cases, and involvement of the skull base and visual dysfunction is rarely reported. However, the optimal treatment and response to treatment of skull base MS in the presence of visual symptoms is unknown.

Case Description:

A 30-year-old male with a history of AML presented with rapidly progressive vision loss and a sellar and parasellar mass with bilateral cavernous sinus and optic nerve encasement. The patient underwent endoscopic endonasal transsphenoidal biopsy revealing intracranial MS. He was treated postoperatively with high-dose intravenous and intrathecal cytarabine and had complete restoration of his vision by postoperative day 11. A systematic review of the literature identified six cases of skull base MS, five of whom presenting with visual symptoms. All patients underwent systemic chemotherapy with cytarabine and/or cyclophosphamide, with infrequent use of intrathecal chemotherapy or radiation. Those with reported visual outcomes were diagnosed 4 months or longer after symptom onset and demonstrated no visual improvement with treatment.

Conclusion:

Skull base MS is a rare disease entity with a high prevalence of visual dysfunction. Our patient’s complete disappearance of intracranial disease and resolution of visual symptoms with systemic and intrathecal chemotherapy highlight the importance of timely diagnosis and appropriate treatment without a need for direct surgical decompression.

The transformation of isolated gastric myeloid sarcoma into acute myeloid leukemia presenting with a complex karyotype and TLS-ERG gene fusion: A case report

RATIONALE

Isolated myeloid sarcoma (MS) is characterized by the rapid proliferation of myeloblasts of acute myeloid leukemia (AML), without any blood or bone marrow involvement. This disease can manifest with extramedullary organ involvement, such as the skin, lymph nodes, bone, brain, breast cervix, and visceral organs, while the occurrence of myeloid sarcomas in the stomach is rare. Isolated MS has been associated with acute myeloid leukemia (AML), but the rapid progression of MS to acute myeloid leukemia with a complex karyotype and TLS-ERG fusion gene is even rarer.

PATIENT CONCERNS

A 33-year-old woman suffered from persistent epigastric pain accompanied by two months of anorexia and nausea, as well as 1-week of melena.

DIAGNOSIS

This patient was initially diagnosed with gastric MS that eventually transformed into AML with a complex karyotype and TLS-ERG fusion gene, 4 months later.

INTERVENTIONS

Only palliative care, including nutrition support, antacids, blood transfusion, anti-infection methods were used on this patient to determine the cachexia status and the family's requirement.

OUTCOMES

Routine follow-up results demonstrated this patient had died due to cerebral hemorrhage five months after the diagnosis of MS.

LESSONS

Comprehensive integration of patient history, imaging features, mass and bone marrow biopsy, and molecular cytogenetic may provide insights that could help us avoid the misdiagnosis of gastric MS. Isolated gastric MS can rapidly progress to AML with a poor prognosis if the patient does not receive appropriate treatment.

Global assessment of IRF8 as a novel cancer biomarker

Interferon regulatory factor 8 (IRF8) is a member of the IRF family that is specific to the hematopoietic cell and is involved in regulating the development of human monocytic and dendritic-lineage cells, as well as B-cells. Because its utility as a sensitive and specific monoblast marker in the context of acute monocytic leukemias has been recently demonstrated, we hypothesized that it may also be useful as a novel immunohistochemical marker in myeloid sarcomas and blastic plasmacytoid dendritic cell neoplasms (BPDCNs) with respect to their differential diagnoses. In this retrospective study, we analyzed the IHC expression pattern of IRF8 in 385 patient samples across 30 types of cancers, referenced to their mRNA expression data available through The Cancer Genome Atlas. In addition, we assessed IRF8 in 35 myeloid sarcomas and 15 BPDCNs. Twenty-four of 35 cases of myeloid sarcomas (68.5%) showed positivity for IRF8, with six cases (17.1%) demonstrating IRF8 expression in the absence of CD34 and MPO. All 15 of 15 BPDCNs (100%) showed strong uniform expression of IRF8 and were occasionally more definitive than CD123. IRF8 was negative in all desmoplastic small round cell tumors, Ewing sarcomas, synovial sarcomas, and undifferentiated pleomorphic sarcomas, as well as all epithelial malignancies tested except for 2 triple negative breast cancers that showed subset weak staining. In conclusion, IRF8 is a novel marker helpful in identifying extranodal hematopoietic tumors that can otherwise be difficult to diagnose given the broad differential diagnoses and frequent loss of more common lineage-defining markers.

Clinical characteristics, pathology features and outcomes of pediatric myeloid sarcoma: A retrospective case series

PURPOSE

Myeloid sarcoma (MS) is a rare extramedullary mass with myeloid expression, which is easy to be missed and misdiagnosed, especially in the pediatric population. We analyze the clinicopathological characteristics, immunophenotypic, cytogenetic, and molecular studies, therapeutic approaches, and outcomes, to optimize the management of such patients.

METHODS

A retrospective, single-center, case series study of eleven children diagnosed with MS by pathology was performed.

RESULTS

The male-to-female ratio was 8:3, and the median age at diagnosis was 7 years. The most commonly involved sites were the skin and orbital region, followed by lymph nodes, central nervous system, and testis. Seven cases (64%) with Class I-MS and four cases (36%) presented as Class II-MS. Immunohistochemically, MPO and CD117 were the most commonly expressed markers, followed by CD33, CD43, CD34, CD68, and lysozyme. Chromosomal abnormalities were detected in 4 patients. Two patients had the presence of deleterious mutations (FLT3, ASXL, KIT, and DHX15) on molecular detection. Ten patients were treated with chemotherapy based on AML regimens. The median follow-up time was 33.5 months in eleven patients. Two patients relapsed, one died, and one lost to follow-up. The 2-year overall survival (OS) rate estimated by Kaplan-Meier curves was 90.9% ± 8.7%, and the event-free survival (EFS) rate was 64.9% ± 16.7%.

CONCLUSIONS

MS diagnosis is usually challenging. Adequate tumor biopsy and expanded immunohistochemistry are necessary for the correct diagnosis of MS. Early and regular systemic chemotherapy promises long-term survival.

Myeloid Sarcoma of the Testis in Children: Clinicopathologic and Immunohistochemical Characteristics With KMT2A (MLL) Gene Rearrangement Correlation

Myeloid sarcoma (MS) is defined as an extramedullary mass-forming lesion composed of immature myeloid cells. It is a rare but well-known manifestation of acute myeloid leukemia. Pediatrics testicular MS may pose a possible diagnostic challenge, an issue that is underscored in the few testicular pediatric MS cases reported in the literature. Herein, we report a series of 5 cases of pediatric testicular MS that are evaluated at the morphologic and immunohistochemical levels with correlation with the KMT2A (MLL) rearrangement status. Three patients presented with no prior history of acute myeloid leukemia. All 5 cases showed monoblastic morphology; positive for CD33, CD43, CD68, CD163, CD4 (dim), and lysozyme; and negative for CD10, CD34, CD117, and myeloperoxidase. KMT2A (MLL) rearrangement was detected in 4 of the 5 cases. In the literature, 8 more cases of pediatric testicular lymphoma were reported. Most of them showed monocytic differentiation and KMT2A (MLL) rearrangement was reported in 3 of the cases. In conclusions, testicular MS in pediatric patients shows monoblastic differentiation which may be attributed to the KMT2A (MLL) rearrangement. We also highlight the importance of using an extended immunohistochemistry panel in the diagnosis of MS.

Post-transplant relapse of therapy-related MDS as gastric myeloid sarcoma: Case report and review of literature

Introduction

Myelodysplastic syndrome (MDS) are hematologic neoplasms characterized by morphologic dysplasia and ineffective hematopoiesis in the bone marrow. The only potentially curative therapy is stem cell transplant. However, relapse remains a major challenge and is seen in about 25–40% of cases. Myeloid sarcoma presenting as relapse post allogeneic transplant for myeloid neoplasms is rare. We report the sentinel case of a patient with MDS who relapsed as gastric myeloid sarcoma 1 ½ years after allogeneic stem cell transplant.

Case Presentation

Sixty-nine-year-old male who was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in 2006 and transitional cell bladder carcinoma in 2008. In 2011, he developed therapy-related myeloid neoplasm t(7;22) and no excess blasts. He was treated with Vidaza followed by a MUD hematopoietic stem cell transplant on 8/24/2012. In 2013 the patient developed anorexia and gastric biopsies showed severe gastritis. Repeat gastric biopsy on 02/05/2014 showed an extensive mononuclear infiltrate which could easily be confused with lymphocytes but staining showed myeloid sarcoma. Marrow was negative. The patient remained refractory to therapy and expired 08/10/2016.

Conclusion

In summary, we report the first case of GI relapse of MDS as a myeloid sarcoma post-transplant. We seek to alert our audience of this potentially serious diagnostic pitfall, particularly one that can be relatively easily resolved on the basis of immunohistochemical profiling.

Granulocytic Sarcoma: A Rare Cause of Wrist Pain

Septic, inflammatory, or crystal-induced arthritis are common etiologies of wrist pain without antecedent trauma associated with pain, loss of motion, swelling, redness, and warmth. In this report, we detail the case of granulocytic sarcoma of the wrist that presented as acute wrist pain, swelling, and limitation in motion. Granulocytic sarcoma is an exceedingly rare extramedullary tumor associated with acute myeloblastic leukemia. It may be found in any part of the body; however, upper extremity involvement is uncommon. To our knowledge, this is the first description of granulocytic sarcoma occurring in the wrist joint.

Diagnosis and surgical treatment of primary isolated aggressive lumbar myeloid sarcoma: a rare case report and review of the literatures

BACKGROUND

Myeloid sarcoma is a rare, extramedullary, solid tumor derived from immature myeloid cell precursors. It is most frequently accompanied by acute myelogenous leukemia, though infrequently found in non-acute myelogenous leukemia patients. The tumor may involve any part of the body, but the lumbar spine is seldom involved. The present case study aims to understand the diagnosis and surgical treatment of a rare primary isolated myeloid sarcoma of the lumbar spine causing aggressive spinal cord compression in a non-acute myelogenous leukemia patient.

CASE PRESENTATION

A 29-year-old man complained of an aggressive radiating pain to the lower extremities and moderate dysuria with a Visual Analogue Scale score that gradually increased from 3 to 8. Lumbar enhanced magnetic resonance imaging and computed tomography revealed a lumbar canal lesion at lumbar spine L2 to L4 with spinal cord compression. A whole body bone scan with fused single photon emission computed tomography/computed tomography demonstrated abnormal ^99mTc-methylene diphosphonate accumulation in the L3 lamina and spinous process. No evidence of infection or hematology disease was observed in laboratory tests. Due to rapid progression of the symptoms and lack of a clear diagnosis, decompression surgery was performed immediately. During the operation, an approximately 6.0 × 2.5 × 1.2 cm monolithic, fusiform, soft mass in the epidural space and associated lesion tissues were completely resected. The radiating pain was relieved immediately and the dysuria disappeared within 1 week. Intraoperative pathological frozen section analysis revealed a hematopoietic malignant tumor and postoperative immunohistochemistry examination confirmed the diagnosis of myeloid sarcoma.

CONCLUSIONS

The primary isolated aggressive lumbar myeloid sarcoma is rarely seen, the specific symptoms and related medical history are unclear. Surgery and hematological treatment are effective for understanding and recognizing this rare tumor.

A case report on concurrent occurrence of systemic mastocytosis and myeloid sarcoma presenting with extensive skin involvements and the results of genetic study

INTRODUCTION

Systemic mastocytosis is a rare disease due to mast cell accumulation in various extracutaneous sites. Systemic mastocytosis with an associated clonal hematologic non-MC lineage disease is the second most common subtype of systemic mastocytosis. The most common mutation associated with both systemic mastocytosis and myeloid sarcoma is mutation in Kit. Here, we identified the novel KIT D816V and ARID1A G1254S mutations co-occurring in systemic mastocytosis with myeloid sarcoma.

PATIENT CONCERNS

A 33-year old male patient presented multiple skin lesions for 10 years. Symptoms accelerated in 2017 with decreased body weight. Physical examination revealed enlarged lymph nodes in his neck, axilla and inguinal region; conjunctival hemorrhage; gingival hyperplasia. Skin biopsy showed mast cell infiltration. Flow cytometry detected CD2, CD25 and CD117 positive cells in lymph nodes. Codon 816 KIT mutation D816V and codon 1245 ARID1A mutation G1254S were found in peripheral blood. MPO, CD117, CD68 positive cells in lymph nodes indicated co-existing myeloid sarcoma.

DIAGNOSIS

Systemic mastocytosis with an associated clonal hematologic non-MC lineage disease of myeloid sarcoma INTERVENTIONS:: Cytarabine and daunorubicin for myeloid sarcoma and dasatinib for systemic mastocytosis were initiated. Anti-histamine and anti-leukotrienes therapy were used to prevent NSAIDs-induced shock. Platelets were infused to treat bone marrow suppression.

OUTCOMES

Patient was discharged after recovered from bone marrow suppression. Dasatinib continued on outpatient.

CONCLUSION

This is the first case of patient with systemic mastocytosis and myeloid sarcoma simultaneously presenting extensive skin involvements. Mutations of Kit and Arid1a emphasis the importance to notice possibility of various tumors occurring in patients with multiple mutations. In addition, cysteine-leukotrienes-receptor antagonists should always be used to prevent anaphylactic shock due to mast cell activation.

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.

Orbital myeloid sarcoma (chloroma): Report of 2 cases and literature review

Purpose

Myeloid sarcoma (MS) of the orbit is an uncommon condition in occurring in children, generally coupled to myeloproliferative neoplasms.

Observations

We describe two rare cases of orbital MS in young boys with aggressive local symptoms but without evidence of acute myeloid leukemia (AML), both patients underwent orbitotomy for gross-tumor resection and biopsy. At follow up, there was no evidence of recurrence nor evolution of the myeloproliferative neoplasms clinically and by radiological and laboratory work-up. We also provide a detailed description of the magnetic resonance imaging presentation, with an extensive pathological analysis correlation.

Conclusions and importance

A comprehensive revision of the literature on isolated orbital MS was carried out with particular emphasis on clues for differential diagnosis and treatment options, stressing the need to consider MS even in the absence of sign and symptoms of an underlying myeloproliferative disorders.

Orbital myeloid sarcoma (chloroma): Report of 2 cases and literature review

Purpose

Myeloid sarcoma (MS) of the orbit is an uncommon condition in occurring in children, generally coupled to myeloproliferative neoplasms.

Observations

We describe two rare cases of orbital MS in young boys with aggressive local symptoms but without evidence of acute myeloid leukemia (AML), both patients underwent orbitotomy for gross-tumor resection and biopsy. At follow up, there was no evidence of recurrence nor evolution of the myeloproliferative neoplasms clinically and by radiological and laboratory work-up. We also provide a detailed description of the magnetic resonance imaging presentation, with an extensive pathological analysis correlation.

Conclusions and importance

A comprehensive revision of the literature on isolated orbital MS was carried out with particular emphasis on clues for differential diagnosis and treatment options, stressing the need to consider MS even in the absence of sign and symptoms of an underlying myeloproliferative disorders.

Epidural myeloid sarcoma as the presenting symptom of chronic myeloid leukemia blast crisis

Epidural myeloid sarcoma revealing chronic myeloid leukemia is scarce. Herein, we describe a patient that presented with back pain and bilateral sciatica secondary to root compression due to epidural deposition of leukemic cells. The magnetic resonance imaging showed epidural masses, causing a slight restriction of the spinal canal with bilateral L5 root compression. Laboratory examinations showed hyperleukocytosis (white blood cell count: 83 × 109/L, absolute neutrophil count: 60 × 109/L). The bone marrow cytology and immunophenotypic findings confirmed the diagnosis of myeloid leukemia. The diagnosis of spinal myeloid sarcoma revealing chronic myeloid leukemia during the blast phase was established. The patient underwent induction chemotherapy. Then, bone marrow cytology revealed less than 3% of blasts, which correspond to cytological remission. Three months later, MRI showed complete disappearance of the epidural masses. A literature review was conducted by searching PubMed using these terms: "Leukemia, Myeloid" AND "Spine" AND "Sarcoma, Myeloid". We emphasize clinical and radiological findings of spinal myeloid sarcoma. This diagnosis should be considered when the MRI reveals epidural mass lesion. The early management of this disease is necessary, and the treatment of myeloid sarcoma is not codified. Our case highlighted that chemotherapy treatment could be sufficient to lead to the disappearance of myeloid sarcoma and the remission of leukemia.

Myeloid Sarcoma With CBFB-MYH11 Fusion (inv(16) or t(16;16)) Prevails in the Abdomen

OBJECTIVES

Myeloid sarcoma with CBFB-MYH11 fusion may be enriched in abdominal sites. The clinicopathologic features of 11 cases are reported.

METHODS

We collected clinical features, morphology, immunophenotype, and bone marrow (BM) involvement of myeloid sarcoma cases with CBFB-MYH11 fusion.

RESULTS

Eleven of 29 total myeloid sarcoma cases were CBFB-MYH11 positive and all 11 involved abdominal sites. The blastic infiltrate was associated with eosinophils in four of 11 cases and plasmacytoid dendritic cell (pDC) nodules in four of six cases. CD34, CD117, and myeloperoxidase were expressed in eight of nine, 10 of 10, and 10 of 10 cases, respectively. Ten of 10 cases showed no BM involvement.

CONCLUSIONS

Our current series, combined with a literature review, identifies a compelling series of 31 (94%) of 33 cases of myeloid sarcoma with CBFB-MYH11 fusion showing a marked predilection for abdominal sites. In addition, the lack of obvious associated eosinophils, presence of pDC nodules, and lack of concurrent BM involvement suggest that "myeloid sarcoma with CBFB-MYH11 fusion" may represent a unique phenomenon.

Isolated myeloid sarcoma presenting with small bowel obstruction: a case report

BACKGROUND

Myeloid sarcoma (MS) is a solid tumor consisting of myeloid blasts or immature myeloid cells, which are unusual outside the bone marrow.

CASE PRESENTATION

We present a rare case of isolated myeloid sarcoma of the small bowel in a 54-year-old man who was admitted to our hospital with repeated symptoms of intestinal obstruction. A small bowel series via an ileus tube revealed severe jejunal obstruction. Computed tomography revealed that the obstruction was likely caused by a jejunal tumor. The patient underwent laparoscopy-assisted partial resection of the jejunum with lymphadenectomy. Histopathological examination of the surgical specimen confirmed that MS had been responsible for the obstruction.

CONCLUSIONS

Patients with MS require systemic chemotherapy, as do patients with acute myeloid leukemia. Hence, an early, accurate diagnosis is imperative for treating this malignancy. It is also important to list MS in the differential diagnosis of a small bowel tumor, even in nonleukemic patients.

Progressive cranial neuropathy and uterine involvement in myeloid sarcoma

A rare extramedullary manifestation of haematological malignancy, myeloid sarcoma is most commonly seen in patients with acute myeloid leukaemia. We report on an adult patient who presented with an atypical phenotype of progressive cranial neuropathy without blood or bone marrow involvement, and in whom obtaining material for pathological diagnosis was made challenging by unusual findings of absent fluorodeoxyglucose-positron emission tomography avidity and involvement of sites not readily accessible to biopsy (orbital apex and cauda equina). The eventual diagnosis was obtained through biopsy of the uterine cervix before being verified on repeat lymph node and cerebrospinal fluid sampling prior to initiation of chemotherapy.

The various clinical spectra of juvenile xanthogranuloma: imaging for two case reports and review of the literature

BACKGROUND

Juvenile xanthogranuloma (JXG) belongs to the heterogeneous group of non-Langerhans cell histiocytosis and is caused by an accumulation and proliferation of macrophages. In the majority of cases JXG is a disorder of early childhood presenting during the first 2 years of life. The typical presentation is a solitary reddish or yellowish skin papule or nodule with spontaneous regression and no need for treatment.

CASE PRESENTATION

Two infants with an atypical presentation of JXG, one with multiple blueberry muffin rash-like skin lesions and the other with severe multi-systemic involvement, are reported. Diagnosis was established by skin biopsy including histological work-up and immunostaining, where markers for macrophages (CD68 and CD163) exhibited significant reactivity.

CONCLUSION

JXG is the most common of the non-Langerhans cell histiocytosis. The typical presentation is a solitary skin lesion. The purpose of this report is to familiarize paediatricians with an unusual variant of this entity in order to facilitate early diagnosis and raise awareness for possible visceral complications and associated medical conditions.

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.

Altered NFE2 activity predisposes to leukemic transformation and myelosarcoma with AML-specific aberrations

In acute myeloid leukemia (AML), acquired genetic aberrations carry prognostic implications and guide therapeutic decisions. Clinical algorithms have been improved by the incorporation of novel aberrations. Here, we report the presence and functional characterization of mutations in the transcription factor NFE2 in patients with AML and in a patient with myelosarcoma. We previously described NFE2 mutations in patients with myeloproliferative neoplasms and demonstrated that expression of mutant NFE2 in mice causes a myeloproliferative phenotype. Now, we show that, during follow-up, 34% of these mice transform to leukemia presenting with or without concomitant myelosarcomas, or develop isolated myelosarcomas. These myelosarcomas and leukemias acquired AML-specific alterations, including the murine equivalent of trisomy 8, loss of the AML commonly deleted region on chromosome 5q, and mutations in the tumor suppressor Trp53 Our data show that mutations in NFE2 predispose to the acquisition of secondary changes promoting the development of myelosarcoma and/or AML.

Cutaneous Metastases: A Review and Diagnostic Approach to Tumors of Unknown Origin

CONTEXT.—

Cutaneous metastases from a distant malignancy are a diagnostic challenge for pathologists. Secondary involvement of the skin by a metastatic process portends a much worse clinical prognosis than any primary cutaneous malignant mimickers. Immunohistochemical staining methods continue to evolve and are of paramount importance in diagnosis.

OBJECTIVE.—

To review the clinical, histopathologic, and immunohistochemical staining patterns for commonly encountered entities and discuss potential pitfalls in diagnosis. A practical guide useful in approaching cutaneous metastases of unknown primary is outlined.

DATA SOURCES.—

An extensive search and review of literature in PubMed was performed, processed, and condensed.

CONCLUSIONS.—

Cutaneous metastases have broad histopathologic patterns. They are nearly always dermal based, with an overall foreign appearance. They can be single papules/nodules or multiple in number, mimicking an inflammatory or infectious process. Ultimately, immunohistochemistry remains an essential diagnostic tool, and clinical correlation is paramount in the workup of these entities.

Myeloid Sarcoma of the Paranasal Sinuses in a Patient with Acute Myeloid Leukemia

Myeloid sarcoma (MS) is an uncommon extramedullary malignant tumor, and often represents a subgroup of acute myeloid leukemia (AML). MS of paranasal sinus origin is extremely rare. We report an uncommon case of sinonasal MS associated with AML, who was successfully treated with hematopoietic stem-cell transplantation. A 39-year-old male was admitted with complaints of left nasal obstruction and proptosis. Computed tomography and magnetic resonance imaging identified a left ethmoidal mass involving the maxillary sinus, the orbit, and the skull base. Nasal endoscopic examination detected a whitish homogeneous mass occupying the left nasal cavity. Although accumulation of atypical lymphocytes was suspected based on initial pathological inspection, immunohistochemical analysis showed myeloperoxidase-positive myeloid cells. Together with concomitant leukocytosis (149,000/µL) composed of myeloid blast cells and excess of myeloblasts in the bone marrow, the patient was diagnosed as sinonasal MS with AML with maturation (French-American-British Classification M2). The patient was treated by chemotherapy (remission induction therapy with daunorubicin and cytarabine; salvage chemotherapy with high-dose cytarabine), radiotherapy (30 Gy in 10 fractions) and allogeneic hematopoietic stem-cell transplantation, and followed up for 12 months with no recurrence. Early diagnosis is critical for the best improvement of MS. MS of the paranasal sinuses may easily be misdiagnosed as malignant lymphoma or poorly differentiated carcinoma. Prompt hematological and immunohistological investigations with suspicion of MS are essential for correct diagnosis. Furthermore, we concisely review nine previously reported patients with MS and indicate the importance of hematopoietic stem-cell transplantation for good prognosis.

Isolated myeloid sarcoma in the pancreas and orbit: A case report and review of literature

Myeloid sarcoma (MS) is a type of extramedullary solid haematological tumour. Myeloid sarcoma is classified into two types based on whether onset of the disease is complicated by haematologic diseases: extramedullary infiltration of leukaemia (leukaemic MS) and isolated myeloid sarcoma. The incidence of isolated myeloid sarcoma is low. In particular, isolated myeloid sarcoma involving the pancreas is extremely rare and prone to misdiagnosis. This case report describes the long and eventful diagnostic process of a case of myeloid sarcoma involving the pancreas and orbit. Due to a lack of typical clinical manifestations and imaging characteristics, the patient underwent several rounds of treatment without a confirmed diagnosis. Eventually, the final diagnosis was pathologically confirmed using several types of biopsies and immunohistochemical detection. To date, this type of disease has not been reported in the literature. This case report describes the detailed diagnostic process and discusses the strategies used for diagnosis, which will facilitate the diagnosis of such diseases in the future.

Peritoneal Myeloid Sarcoma in a Patient Treated for a Testicular Seminoma

BACKGROUND Myeloid sarcoma is a rare extramedullary soft tissue neoplasm composed of myeloblastic cells, usually associated to hematologic tumor disorders and a poor prognosis. Its diagnosis is very difficult as radiological images are not specific. Histology and immunohistochemistry are necessary for an accurate diagnosis. CASE REPORT We report the case of 46-year-old, Caucasian, non-smoker male, treated in 2014 by orchiectomy and systemic chemotherapy for a stage IIB testicular seminoma. Considering the rapid increase of lactate dehydrogenase (LDH) levels without any evident medical reason, a computed tomography/positron emission tomography (CT/PET) scan was performed and revealing a diffuse, nodular, peritoneal tumor infiltration associated with multiple mesenteric and mediastinal adenopathies. Laparoscopy confirmed a diffuse tumor infiltration of the peritoneum. Histology and immunohistochemistry were consisted with the diagnosis of a myeloid monoblastic sarcoma. Cytology of bone marrow documented an monocytic acute myeloid leukemia. The patient started a systemic induction chemotherapy with high dose cytarabine and idarubicin that was complicated by an infectious pneumonia and colitis, and a grade IV thrombocytopenia leading to a brain subdural hemorrhage and quickly to patient's death. CONCLUSIONS We describe a rare, peritoneal, myeloid sarcoma in a young patient who had been treated by systemic chemotherapy for testicular seminoma 4 years earlier. The patient was clinically asymptomatic and presented only elevated LDH levels without any evident clinical reason. Considering the persistence of this biochemical abnormality, more investigations were performed leading to a diagnosis of peritoneal myeloid sarcoma associated with monocytic acute myeloid leukemia, probably secondary to the past chemotherapy.

Myeloid sarcoma of the small intestine in a patient without overt acute myeloid leukaemia: a challenging diagnosis of a rare condition

Myeloid sarcoma (MS) is a rare condition that most commonly occurs in the setting of acute myeloidleukaemia (AML) or other chronic myeloproliferative disorders. It presents as an abnormal growth that can develop anywhere in the human body, and its clinical manifestations are often non-specific.We present the case of a patient admitted to the emergency room with bowel obstruction. After careful clinical assessment, she underwent a right hemicolectomy. After a thorough examination of the surgical pathology specimen, including testing a wide array of immunohistochemical markers, the patient was timely diagnosed with MS, allowing for the implementation of the appropriate treatment to achieve complete remission. This is crucial, since non-leukaemic patients with untreated MS always progress to AML, and have a better prognosis if adequate therapy is implemented early. Our patient is now in the second postoperative year and shows no signs of relapse.

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.

An improved pre-clinical patient-derived liquid xenograft mouse model for acute myeloid leukemia

Background

Xenotransplantation of patient-derived AML (acute myeloid leukemia) cells in NOD-scid Il2rγ^null (NSG) mice is the method of choice for evaluating this human hematologic malignancy. However, existing models constructed using intravenous injection in adult or newborn NSG mice have inferior engraftment efficiency, poor peripheral blood engraftment, or are difficult to construct.

Methods

Here, we describe an improved AML xenograft model where primary human AML cells were injected into NSG newborn pups intrahepatically.

Results

Introduction of primary cells from AML patients resulted in high levels of engraftment in peripheral blood, spleen, and bone marrow (BM) of recipient mice. The phenotype of engrafted AML cells remained unaltered during serial transplantation. The mice developed features that are consistent with human AML including spleen enlargement and infiltration of AML cells into multiple organs. Importantly, we demonstrated that although leukemic stem cell activity is enriched and mediated by CD34⁺CD117⁺ subpopulation, CD34⁺CD117⁻ subpopulation can acquire CD34⁺CD117⁺ phenotype through de-differentiation. Lastly, we evaluated the therapeutic potential of Sorafenib and Regorafenib in this AML model and found that periphery and spleen AML cells are sensitive to these treatments, whereas BM provides a protective environment to AML.

Conclusions

Collectively, our improved model is robust, easy-to-construct, and reliable for pre-clinical AML studies.

Electronic supplementary material

The online version of this article (10.1186/s13045-017-0532-x) contains supplementary material, which is available to authorized users.

Initial Diagnostic Workup of Acute Leukemia: Guideline From the College of American Pathologists and the American Society of Hematology

CONTEXT

- A complete diagnosis of acute leukemia requires knowledge of clinical information combined with morphologic evaluation, immunophenotyping and karyotype analysis, and often, molecular genetic testing. Although many aspects of the workup for acute leukemia are well accepted, few guidelines have addressed the different aspects of the diagnostic evaluation of samples from patients suspected to have acute leukemia.

OBJECTIVE

- To develop a guideline for treating physicians and pathologists involved in the diagnostic and prognostic evaluation of new acute leukemia samples, including acute lymphoblastic leukemia, acute myeloid leukemia, and acute leukemias of ambiguous lineage.

DESIGN

- The College of American Pathologists and the American Society of Hematology convened a panel of experts in hematology and hematopathology to develop recommendations. A systematic evidence review was conducted to address 6 key questions. Recommendations were derived from strength of evidence, feedback received during the public comment period, and expert panel consensus.

RESULTS

- Twenty-seven guideline statements were established, which ranged from recommendations on what clinical and laboratory information should be available as part of the diagnostic and prognostic evaluation of acute leukemia samples to what types of testing should be performed routinely, with recommendations on where such testing should be performed and how the results should be reported.

CONCLUSIONS

- The guideline provides a framework for the multiple steps, including laboratory testing, in the evaluation of acute leukemia samples. Some aspects of the guideline, especially molecular genetic testing in acute leukemia, are rapidly changing with new supportive literature, which will require on-going updates for the guideline to remain relevant.

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.

Invasive Fungal Infection in Acute Myeloid Leukemia Associated with Myeloid Sarcoma of the Sinonasal Cavity: A Rare Case

Myeloid sarcoma is a rare malignant extramedullary neoplasm of myeloid precursor cells. The majority of these cases occur in patients with known leukemia or those who eventually develop the disease. It can occur in various sites but sinonasal cavity involvement along with invasive fungal infection is exceedingly rare.

Clinical characteristics, molecular profile and outcomes of myeloid sarcoma: a single institution experience over 13 years

BACKGROUND

Myeloid sarcoma (MS) is characterized by extramedullary infiltration by immature myeloid cells. Owing to rarity of this disease, the clinical features and overall outcomes are yet to be clarified.

OBJECTIVE

To define clinical characteristics, epidemiology, pathologic findings, treatment options and outcomes in MS.

METHODS

We conducted a retrospective review of 23 patients diagnosed with MS at our institute over a period of 13 years (2002-2015).

RESULTS

MS presented mostly as a manifestation of relapsed acute myeloid leukemia, seen in 39% of patients. Skin and subcutaneous soft tissues were the most common sites of anatomic involvement (69.5%). Ninety five percent (n = 19) were positive for classical myeloid markers with either cytochemical staining (chloracetate-esterase, MPO), flow-cytometry (CD33, CD34, CD13 and CD117), or immunohistochemistry (CD34, CD43, CD68 and lysozyme). Of these, 52% were positive for CD33 (n = 12), 35% for CD68 (n = 8), 30% for CD34 (n = 7), and 26% for lysozyme (n = 6). Cytogenetic abnormalities were seen in 63% (n = 12/19) patients on bone-marrow aspirate, with five patients displaying a complex (n = 3) or monosomal (n = 2) karyotype. Twenty seven percent patients with a normal karyotype had presence of deleterious mutations (FLT3, ASXL, STAG and JAK2) on further testing with myeloid mutation panel. The Median overall survival (OS) of the entire cohort was 15.9 months (95% CI, 7.4-24.4 months). The OS was significantly better for patients <65 years (24.6 vs. 3.4 months, p = 0.009) of age, and for those attaining a complete remission (CR) to induction therapy (25.7 vs. 0.8 months, p < 0.001). All patients who underwent allogeneic hematopoietic stem cell transplant attained long-term remissions, with a median follow-up of 54 (range 32-120) months.

CONCLUSION

Failure to achieve CR with induction therapy, and age >65 years are associated with poor outcomes in MS. Allogeneic stem-cell transplant in first remission appears to be the most effective modality for achieving long-term remissions.