Myeloid sarcoma

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.

A Review of Pediatric Ophthalmic Tumors

Tumors of the eye, orbit, and ocular adnexa can arise in the pediatric population. These entities can be both vision- and life-threatening and may be associated with systemic disease. Given their relative rarity, pediatricians must be aware of these conditions and understand what findings warrant immediate referral to an ophthalmologist for initiation of further testing. We aimed to review these conditions and highlight clinical features to promote awareness and expedite diagnosis. Tumors are subdivided into the following categories for review: anterior tumors of the eyelid and ocular surface, orbital tumors, and intraocular tumors.

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.

Gastric Myeloid Sarcoma

Most gastric cancers are adenocarcinomas, but other malignancies can arise in the stomach. Patients with leukemia may develop myeloid sarcoma (MS) in the gastrointestinal tract. Our patient was a 68-year-old woman who was initially diagnosed with acute myeloid leukemia and underwent a matched unrelated stem cell transplantation. She was in remission for 10 years before developing a rare case of gastric MS without acute myeloid leukemia. She had partial response to chemotherapy but ultimately died because of infection. Gastric MS has an incidence of less than 1%. Gastrointestinal involvement usually involves the small intestine and rarely the stomach.

Primary non leukemic myeloid sarcoma of the ureteral wall: a case report of a rare disease

Myeloid sarcoma (MS) is an extramedullary tumor mass causing proliferation of mature or immature blast cells of one or more myeloid lineages. Involvement of the genitourinary tract is rare. We present a case of MS of the ureteral wall. A 74-year-old man was evaluated for left hydronephrosis and ipsilateral low back pain. A computed tomography scan showed a nodular formation in the pelvic ureter. Urinary cytology revealed cellular atypia, so ureteroscopy was performed showing a distal ureteral mass. The histological examination of the biopsy revealed to be malignant neoplasm. The patient underwent left laparoscopic nephroureterectomy with bladder cuff excision. Microscopic histological examination revealed a tumor compatible with MS. A postoperative positron emission tomography revealed residual hypercaptation of the bladder, pelvic muscle and iliac nodes, so the patient started chemotherapy. A multidisciplinary approach was required, taking into account the patient's age, the already poor renal function and the location of the neoplasm.

Myeloid Sarcoma of the Breast: A Diagnostic Dilemma With Pathologic Correlation

Myeloid sarcoma (MS) is a rare extramedullary solid tumor arising most often in patients with current or subsequent acute myeloid leukemia (AML). Patients of all ages may present with involvement of the skin, lymph nodes, intestinal tract, bone, and/or central nervous system. Isolated involvement of the breast is rare, and only a small number of cases have been described in the literature. Breast MS may present as a palpable mass on clinical evaluation. In this broad literature review from 2010 to 2022, the most common findings on mammography are either solitary or multiple masses, followed by architectural distortion and, less commonly, no discrete findings. Sonography may demonstrate hypoechoic or mixed echogenicity mass(es) with circumscribed or indistinct, not discrete margins. Myeloid sarcoma may present as an enhancing mass or nonmass enhancement on breast MRI and is typically moderately radiotracer avid on 18F-fluorodeoxyglucose-PET. At histopathology, MS is characterized by myeloid blasts in varying stages of granulocytic or neutrophilic maturation; diagnosis typically requires immunophenotyping. There is no consensus for treatment of MS, although systemic chemotherapy for AML is often used as MS is considered the tissue equivalent of AML. This article will discuss and illustrate imaging and pathology findings when the breast is involved by MS.

Regression of a Myeloid Sarcoma of the Nasal Cavity With Extension to the Cheek After Radiotherapy

Myeloid sarcoma is rare and nasal chloroma is an uncommon initial manifestation of acute myeloid leukaemia. The correct diagnosis is a big challenge. In this report, we present a case of myeloid sarcoma of the nasal cavity with extension to the soft tissues of the face. A 53-year-old woman with a past medical history of thalassemia, not followed up, presented with a progressive greyish swelling in her right cheek associated with a nasal obstruction more marked on the right side and unilateral lacrimation. The diagnosis of myeloid sarcoma was based on histopathology and immunohistochemistry. Bone marrow aspiration testing revealed blasts that met the criteria for acute leukaemia. She received external radiotherapy at a total dose of 30 Gy in 15 fractions without systemic therapy, because she refused to get chemotherapy. She remained under surveillance and symptomatic treatment. The patient was examined four months after the end of the irradiation and showed a spectacular improvement in her clinical symptomatology with a clear decrease in nasal mass.

De novo myeloid sarcoma mimicking gynecological tumors: a retrospective case series of eight patients

OBJECTIVE

To describe myeloid sarcoma (MS) that mimic gynecological tumors and provide guidelines for improving the diagnosis and treatment of patients.

METHODS

This case series study retrospectively analyzed the clinicopathological characteristics and oncological outcomes of female patients who were histologically diagnosed with MS after initially presenting with reproductive-system tumors at the Peking Union Medical College Hospital between January 2000 and March 2022.

RESULTS

There were eight cases in which MS mimicked cervical cancer, ovarian cancer, or hysteromyoma. Six patients had isolated MS, and the other two had acute myeloid leukemia (AML)-M2. The average age was 39.00 ± 14.26. They each sought advice from a gynecological oncologist at the initial visit, complaining of irregular bleeding (3/8), low abdominal pain (3/8), dysmenorrhea (1/8), or an accidentally found mass (1/8). CT/MRI exams revealed that the average tumor size reached 5.65 ± 2.35 cm, with 50% of the tumors being larger than 8 cm. The final diagnoses were confirmed by biopsy (2/8) or postoperative pathology (6/8); the most frequent positive immunohistochemical markers were Ki-67 (60-90%), MPO (100%), LCA (62.5%), CD43 (62.5%), CD117 (62.5%), CD99 (50%), vimentin (37.5%), and lysozyme (25%). MLL/AF9 gene fusions and CEBPA, JAK2, NRAS, and FLT3-TKD mutations were found in the patients. Six (75%) of the patients showed a complete response after upfront treatment using chemotherapy + surgery and experienced no recurrence during follow-up. The overall survival (OS) rate was 72.9%, and the 5-year OS rate was 72.9% (95%CI: 0.4056-1.000). The median OS was 26 months (range: 3-82).

CONCLUSION

For patients with isolated MS, treatment by chemotherapy and surgery are radical procedure, and initial treatment using chemotherapy alone should be considered for MS with synchronous intramedullary AML. Poor response to chemotherapy, short interval to leukemia occurrence, and heavy tumor burden (> 10 cm) could indicate a poor prognosis for patients with MS.

RNA sequencing of myeloid sarcoma, shed light on myeloid sarcoma stratification

BACKGROUND

Myeloid sarcoma (MS) is a rare, extramedullary tumor consisting of myeloid blasts. Little is known about the genetic background of MS and the prognostic value of genetic abnormalities in MS. In particular, the broad variety of gene fusions that occur in MS is marginally covered by traditional testing methods due to lack of fresh tumor specimens.

METHODS

Here, we analyzed the clinical and genetic features of 61 MS cases. We performed RNA sequencing (RNA-seq) on formalin-fixed paraffin-embedded (FFPE) or fresh samples to analyze fusion genes in 26 cases. In addition, we performed genetic abnormalities-based risk stratification using fusion genes and gene mutations.

RESULTS

A total of 305 fusion genes were identified in 22 cases, including the following five recurrent fusion genes: RUNX1-RUNX1T1, CBFβ-MYH11, ETV6-MECOM, FUS-ERG, and PICALM-MLLT10. The prognosis in the adverse-risk group was significantly worse than that in the favorable/intermediate-risk group (median survival: 12 months vs. not reached; p = 0.0004).

CONCLUSION

These results indicated the efficacy of RNA-seq using FFPE-derived RNA as a clinical routine for detecting fusion genes, which can be used as markers for risk stratification in MS.

Gene Mutations and Targeted Therapies of Myeloid Sarcoma

OPINION STATEMENT

Myeloid sarcoma, a rare malignant tumor characterized by the invasion of extramedullary tissue by immature myeloid cells, commonly occurs concomitantly with acute myeloid leukemia, myelodysplastic syndromes, or myeloproliferative neoplasms. The rarity of myeloid sarcoma poses challenges for diagnosis and treatment. Currently, treatments for myeloid sarcoma remain controversial and primarily follow protocols for acute myeloid leukemia, such as chemotherapy utilizing multi-agent regimens, in addition to radiation therapy and/or surgery. The advancements in next-generation sequencing technology have led to significant progress in the field of molecular genetics, resulting in the identification of both diagnostic and therapeutic targets. The application of targeted therapeutics, such as FMS-like tyrosine kinase 3(FLT3) inhibitors, isocitrate dehydrogenases(IDH) inhibitors, and the B cell lymphoma 2(BCL2) inhibitors, has facilitated the gradual transformation of traditional chemotherapy into targeted precision therapy for acute myeloid leukemia. However, the field of targeted therapy for myeloid sarcoma is relatively under-investigated and not well-described. In this review, we comprehensively summarize the molecular genetic characteristics of myeloid sarcoma and the current application of targeted therapeutics.

C1Q labels a highly aggressive macrophage-like leukemia population indicating extramedullary infiltration and relapse

Extramedullary infiltration (EMI) is a concomitant manifestation that may indicate poor outcome of acute myeloid leukemia (AML). The underlying mechanism remains poorly understood and therapeutic options are limited. Here, we employed single-cell RNA sequencing on bone marrow (BM) and EMI samples from a patient with AML presenting pervasive leukemia cutis. A complement C1Q+ macrophage-like leukemia subset, which was enriched within cutis and existed in BM before EMI manifestations, was identified and further verified in multiple patients with AML. Genomic and transcriptional profiling disclosed mutation and gene expression signatures of patients with EMI that expressed high levels of C1Q. RNA sequencing and quantitative proteomic analysis revealed expression dynamics of C1Q from primary to relapse. Univariate and multivariate analysis demonstrated adverse prognosis significance of C1Q expression. Mechanistically, C1Q expression, which was modulated by transcription factor MAF BZIP transcription factor B, endowed leukemia cells with tissue infiltration ability, which could establish prominent cutaneous or gastrointestinal EMI nodules in patient-derived xenograft and cell line-derived xenograft models. Fibroblasts attracted migration of the C1Q+ leukemia cells through C1Q-globular C1Q receptor recognition and subsequent stimulation of transforming growth factor β1. This cell-to-cell communication also contributed to survival of C1Q+ leukemia cells under chemotherapy stress. Thus, C1Q served as a marker for AML with adverse prognosis, orchestrating cancer infiltration pathways through communicating with fibroblasts and represents a compelling therapeutic target for EMI.

Extramedullary Myeloid Leukemia in the Setting of a Myeloproliferative Neoplasm

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

Myeloid sarcoma with ulnar nerve entrapment: A case report

BACKGROUND

Myeloid sarcoma (MS) is relatively rare, occurring mainly in the skin and lymph nodes, and MS invasion of the ulnar nerve is particularly unusual. The main aim of this article is to present a case of MS invading the brachial plexus, causing ulnar nerve entrapment syndrome, and to further clinical understanding of the possibility of MS invasion of peripheral nerves.

CASE SUMMARY

We present the case of a 46-year-old man with a 13-year history of well-treated acute nonlymphocytic leukaemia who was admitted to the hospital after presenting with numbness and pain in his left little finger. The initial diagnosis was considered a simple case of nerve entrapment disease, with magnetic resonance imaging showing slightly abnormal left brachial plexus nerve alignment with local thickening, entrapment, and high signal on compression lipid images. Due to the severity of the ulnar nerve compression, we surgically investigated and cleared the entrapment and nerve tissue hyperplasia; however, subsequent pathological biopsy results revealed evidence of MS. The patient had significant relief from his neurological symptoms, with no postoperative complications, and was referred to the haemato-oncology department for further consultation about the primary disease. This is the first report of safe treatment of ulnar nerve entrapment from MS. It is intended to inform hand surgeons that nerve entrapment may be associated with extramedullary MS, as a rare presenting feature of the disease.

CONCLUSION

MS invasion of the brachial plexus and surrounding tissues of the upper arm, resulting in ulnar nerve entrapment and degeneration with significant neurological pain and numbness in the little finger, is uncommon. Surgical treatment significantly relieved the patient’s nerve entrapment symptoms and prevented further neurological impairment. This case is reported to highlight the rare presenting features of MS.

Hoxa11-mediated reduction of cell migration contributes to myeloid sarcoma formation induced by cooperation of MLL/AF10 with activating KRAS mutation in a mouse transplantation model

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Acute myeloid leukemia (AML) patients with MLL translocations (MLL-t) are frequently found to harbor N-/K-RAS activating mutations.

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Mouse models revealed that cooperating mutations accelerated leukemia development and myeloid sarcoma formation.

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The molecular mechanism of accelerated leukemia development and myeloid sarcoma formation is not clear.

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In this study, we demonstrate Hoxa10 accelerated leukemia development and are the first to show that Hoxa11 controls migration and retention of leukemia cell at extramedullary sites and is a key player in myeloid sarcoma formation.

The molecular mechanism of myeloid sarcoma (MS) formation remains nuclear. Our clinical and mouse model findings from a previous study revealed that cooperation of KMT2A (MLL) translocation (MLL-t) with activating N-/K-RAS mutations promoted MS formation in a shorter latency. To improve the understanding of MS formation, in this study, we performed imaging cell trafficking analysis and demonstrated that cells harboring cooperating mutations migrated more slowly to omental adipose tissues and more cells were retained in adipose tissues in vivo. Comparison of transcriptome profiling among three pairs of mouse MLL/AF10(OM-LZ) leukemia cell lines harboring activating and wild-type KRAS identified 77 differentially expressed genes (DEGs) with >1.5-fold change. Functional annotation of these 77 DEGs using Gene Ontology (GO) enrichment analysis followed by cluster analysis revealed that GO terms related to development/differentiation have the highest enrichment score. The roles of Hoxa10 and Hoxa11, two genes which mapped to this cluster, were further characterized. Silencing Hoxa10 and Hoxa11 in cells harboring cooperating mutations prolonged the survival and reduced MS formation, respectively, in the recipient mice. Data of imaging cell trafficking as well as competitive engraftment and clonal expansion analyses indicated that silencing or overexpressing Hoxa11 in mouse leukemia cells affected cell migration and retention in omental adipose tissue. Although silencing Hoxa11 in leukemia cells did not affect Cxcr4 expression, it resulted in increased transwell migration, motility in confined spaces 3 μm in size, and cell protrusion. Our results revealed that Hoxa10 plays an important role in survival and Hoxa11 contributes to MS formation in MLL-t acute myeloid leukemia with activating KRAS mutation.

Bladder Myeloid Sarcoma with TP53 mutated Myelodysplastic Syndrome/Myeloproliferative Neoplasm Overlap syndrome: Response to Decitabine-Venetoclax regimen

Myeloid sarcoma (MS) is a rare extramedullary blast proliferation of immature cells of myeloid origin. It is commonly associated with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or myeloproliferative neoplasm (MPN), and may precede, coincide with, or follow the diagnosis of a myeloid disorder. MS treatment is controversial, but AML induction like regimens is usually recommended. We present an unusual case of de novo TP53 mutated MDS/MPN overlap with bladder MS. Due to the high-risk nature of the disease, the patient was induced with decitabine and venetoclax combination therapy, resulting in complete remission. The response was further consolidated by an allogeneic hematopoietic stem cell transplantation.

Isolated Myeloid Sarcoma: A Diagnostic Dilemma

Myeloid sarcoma (MS)/granulocytic sarcoma/myeloblastoma/chloroma is a rare extramedullary proliferation of blast cells of one or more myeloid lineages along with the destruction of the normal architecture of adjacent tissue. Isolated MS is a rare entity with an incidence of 0.7 out of 1 million children and 2 out of 1 million adults. Varied clinical presentation, the rarity of the diagnosis, inadequate immunophenotyping, and lack of available literature makes the disease difficult to manage. Here, we report a case of MS in a 44-year-old male with an initial presentation of testicular mass without bone marrow involvement, causing diagnostic challenges. In this case report, we discuss the pathogenesis, diagnostic challenges, and therapeutic options of MS.

Spine Myeloid Sarcoma: A Case Series with Review of Literature

Myeloid sarcoma (MS) is a malignant extramedullary tumor consisting of immature cells of myeloid origin. It may precede, present concurrently or follow acute myeloid leukemia (AML) in de novo case or may also be present and might be the only manifestation of recurrent AML, myelodysplastic syndrome, or chronic myeloid leukemia. It frequently involves skin, orbit, bone, periosteum, lymph nodes, and gastrointestinal tract, soft tissue, central nervous system, and testis. Because of its different localization and symptoms, and the lack of diagnostic algorithm, MS is a real diagnostic challenge particularly in patients without initial bone marrow involvement. The correct diagnosis of MS is important for optimum therapy, which is often delayed because of a high misdiagnosis rate. We reported three cases of MS derived from spine presented with back pain, paraplegia, paraparesis, respectively, and reviewed the relevant literature.

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

Introduction

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

Purpose and methods

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

Results

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

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

Conclusion

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

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

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

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

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

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Allogeneic hematopoietic transplant may be considered in first complete remission.

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

Breast myeloid sarcoma presenting as a palpable breast lump after allogeneic stem cell transplantation for acute myelomonocytic leukemia: a rare case report

Background

Myeloid sarcoma (MS) is a tumor secondary to myeloid leukemia that consists of immature granulocytes with or without mature granulocytes and is a rare extramedullary manifestation of acute myeloid leukemia (AML).

Case presentation

We report a case of a 34-year-old woman diagnosed with AML-M4 who achieved remission after chemotherapy and received allogeneic stem cell transplantation (allo-SCT) for consolidation. Her past medical history showed that she received bilateral breast implants 7 years ago. This patient underwent ultrasound examination of the breast and multiple bilateral breast nodules were revealed that were not considered by clinicians to be concerning. Several months later, the patient’s bilateral nodules rapidly progressed to large palpable masses. Ultrasound-guided biopsy revealed diffuse infiltration of undifferentiated tumor cells and immunohistochemistry (IHC) indicated that the tumor was positive for myeloperoxidase (MPO), cluster of differentiation (CD) 34, CD43, CD68, CD117, and Ki67. The pathological diagnosis was extramedullary recurrence of AML as MS of breast. After the diagnosis, the patient received systemic chemotherapy and drugs containing cytarabine, azacitidine, and methotrexate. However, 1 year after achieving partial remission, the patient died from intracranial invasion of leukemia, brain herniation, and respiratory failure.

Conclusion

It is necessary for the specialist to have a high suspicion index by careful inquiry of the patient’s medical history if a patient presents at the breast clinic with a breast tumor as the chief complaint. Combining information from the patient’s medical history with a tumor biopsy is critical for obtaining the correct diagnosis of the disease.

Clinical and molecular characterization of myeloid sarcoma without medullary leukemia

Myeloid sarcoma (MS) in the setting of concomitant medullary AML is relatively well described, while much less is known about patients presenting with MS with <20% bone marrow blasts. We conducted a retrospective analysis of 56 patients with MS with <20% marrow blasts seen at MD Anderson between 2005 and 2020. The prevalence of MS without medullary AML was 1.4% among all newly diagnosed AML patients. The majority (75%) of patients had a single known anatomic site involved, with the skin (34%) being the most frequent. The most common histologic subtype was monocytic, and 11% of patients had a known history of an antecedent hematologic disorder. The majority of patients (70%) received frontline intensive chemotherapy induction, with 75% of those evaluable attaining complete or partial responses. The median overall survival (OS) and event-free survival (EFS) were 3.41 and 3.07 years, respectively. Patients with bone marrow blasts of ≥5% or medullary relapse had inferior outcomes, while age (>60 years) was not associated with outcomes. There was a suggestion that patients with isolated leukemia cutis may have had better outcomes compared to patients with other organ involvement, but this did not reach statistical significance. Most patients who had cytogenetic analysis had a diploid karyotype within their MS and bone marrow. RAS pathway mutations were enriched in MS at diagnosis, and at time of medullary relapse. Our study provides a large dataset summarizing the clinical and molecular analysis of patients with MS with <20% BM blasts and suggests that monitoring for medullary leukemia is important for early detection of relapse.

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

Background

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

Case presentation

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

Conclusions

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

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

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

Myeloid Sarcoma: Diagnostic and Treatment Tools from a Monocentric Retrospective Experience

Myeloid sarcoma (MS) is a very rare disease in both adults and children. Prognosis is poor in adults; in the pediatric age, the prognostic impact of extramedullary disease is controversial. Systemic therapy represents the mainstay of treatment even in isolated MS, but a comparison between different induction regimens is very limited in the literature. To date, it is still not clear if induction treatment should differ from that of other acute myeloid leukemias and stem cell transplant is considered for consolidation in both leukemic patients and in those with isolated disease. Our study describes a retrospective series of 13 cases of MS (adults and children), diagnosed and treated at our institute over 18 years. We report the results of immunophenotypic, cytogenetic and molecular studies, therapeutic approaches, and outcome, in order to establish the best strategy for patients' workup.

CT classification of acute myeloid leukemia with pulmonary infiltration

PURPOSE

To characterize and categorize the CT findings of pulmonary leukemic infiltration (PLI) in patients with acute myeloid leukemia (AML).

MATERIALS AND METHODS

Among 435 patients with AML, 20 patients with PLI were retrospectively selected, and clinical characteristics and CT findings were analyzed. PLI was categorized into four patterns according to CT findings: type A, multiple nodules and/or masses; type B, bilateral perihilar airspace opacities (GGA or consolidation) without any nodules or masses; type C, mixture of type A and B; and type D, PLI without visible abnormal lung opacity. The difference in overall survival among four CT patterns was also examined.

RESULTS

The frequency of complex karyotypes was higher in AML patients with PLI than in whole AML patients. Percentages of patients with CT findings of type A, B, C, and D were 35%, 20%, 35%, and 10%, respectively. There was a clear difference in the localization of opacities according to the type of infiltrates, i.e., nodules/masses were mainly detected in the lower/peripheral portion. Conversely, GGA was mainly located in the upper/central portion. The median overall survival from diagnosis of PLI was 262 days (range 12-1148). The CT pattern was not significantly associated with survival (p = 0.3), with the exception of patients with type C tending to have significantly better outcomes compared to patients with type B (p = 0.05).

CONCLUSION

This classification can contribute in accurate non-invasive diagnosis and possibly in the estimation of prognosis.

An advanced case of gastric histiocytic sarcoma treated with chemotherapy and gastrectomy: a case report and review of literature

Histiocytic sarcoma is a relatively new disease category and the gastrointestinal origin is sporadic. We report a case of a 74-year-old woman who underwent chemotherapy and proximal gastrectomy for extremely rare, advanced gastric histiocytic sarcoma. The resected specimen was subjected to numerous immunostainings to meet the diagnostic criteria of histiocytic sarcoma and was positive for the histiocyte markers' cluster of differentiation 68 and lysozyme. The markers of Langerhans cells, follicular dendritic cells, and myelocyte were all negative. Six reports of surgical resection of histiocytic sarcoma originating in the stomach exist, including our case. We reviewed the clinical course and the histological and immunohistochemical diagnostic features of surgically resected gastric histiocytic sarcoma.

Extramedullary Involvement in Acute Myeloid Leukemia. A Single Center Ten Years' Experience

The incidence, risk factors, and prognostic significance of extramedullary involvement (EMI) in adult patients with acute myeloid leukemia (AML) have not been established yet. This study analyzed clinical and biological characteristics, the impact on prognosis, and the cumulative incidence of EMI in a monocentric retrospective series. All adult patients diagnosed with AML observed in our institution between January 2010 and December 2017 were included in the analysis. Overall, 346 AMLs were analyzed. The incidence of EMI was 11% (38 patients). The involved sites were: skin (66%), central nervous system (CNS) (23%), pleura (7%), lymph nodes (5%), peritoneum (2%), spleen (2%), pancreas (2%), breasts (2%) and bones (2%). Most patients (91%) had only one EMI site, while 9% had multiple sites affected at the same time. Twenty-four (63%) patients showed signs of EMI at presentation, while extramedullary relapse occurred in 10 patients (26%); 4 patients had EMI both at presentation and relapse. EMI had a significantly higher frequency in patients with monocytic and myelo-monocytic leukemia subtypes (p<0,0001), CD117-negative (p=0,03) at flow cytometry analysis, MLL rearrangements (p=0.001), trisomy 8 (p=0,02). An analysis regarding treatment, overall survival (OS), and disease-free survival (DFS) was performed only on the 28 patients who experienced EMI at the onset of their disease; one EMI patient receiving best supportive care was excluded from OS analysis. The other 27 patients were treated with: conventional chemotherapy (21 patients), hypomethylating agents (5 patients), and low dose cytarabine (1 patient); 8 patients only (28.5%) received an allogeneic stem cell transplantation (allo-HSCT). After induction therapy, complete remission (CR) rate was 22%, with a median DFS of 7.4 months. The median OS of all 27 EMI patients was 11.6 months (range 2-79); this resulted significantly longer for the 8 EMI patients who undergone allo-HSCT than those (19 patients) who did not receive this procedure (16.7 vs. 8.2 months respectively, p=0.02). Univariate and multivariate analyses showed that undergoing allo-HSCT and achieving CR were the main positive prognostic factors for our population's survival (p<0,0001). This study confirms the poor prognosis for EMI patients. Allo-HSCT, applicable however only in some cases, seems to have a crucial role in these patients' therapeutic approach, being associated with a better prognosis.

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

BACKGROUND

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

CASE PRESENTATION

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

CONCLUSIONS

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

[Spontaneous remission of cutaneous myeloid sarcoma]

INTRODUCTION

Cutaneous myeloid sarcoma is a rare extramedullary tumour of immature myeloid cells. It is most often associated with acute myeloid leukaemia, and more rarely with myelodysplastic/myeloproliferative disease.

PATIENTS AND METHODS

Herein we report a case of cutaneous myeloid sarcoma associated with myelodysplastic/myeloproliferative disease in an 84-year-old man with a diffuse purple papular and nodular rash. The disease course was marked by a spontaneous and total regression for two months. Given the patient's age and general condition, chemotherapy could not be given.

DISCUSSION

Cutaneous myeloid sarcoma is rare. It is often associated with acute myeloid leukaemia, and more rarely with myelodysplastic/myeloproliferative disease, but it can occur in isolation. Diagnosis is particularly difficult and is based a consistent body of clinical and histological evidence. Spontaneous regression is very rare and involves immunological mechanisms that are still incompletely understood. Recurrence occurs within a variable time frame and is often associated with transformation to acute myeloid leukaemia if this was not already present at the time of diagnosis.

CONCLUSION

Herein we report an extremely rare case of spontaneous regression of cutaneous myeloid sarcoma associated with myelodysplastic/myeloproliferative disease.

Pancreatic Myeloid Sarcoma

Myeloid sarcoma is an isolated extramedullary tumor mass consisting of immature myeloid cells. It is characterized by highly variable outcomes and usually disrupts the normal architecture of the normal tissue in which it originates. It may occur de novo or be associated with other hematological malignancies. Clinical presentation of myeloid sarcomas can be highly variable based on the tumor site, size, and extent of tissue involvement. The diagnosis of myeloid sarcoma is challenging and requires a high index of suspicion. Tissue sampling followed by the use of auxiliary studies is essential for diagnosis. Moreover, bone marrow sampling is necessary to exclude morrow involvement. Currently, the recommended therapeutic regimens for myeloid sarcoma are similar to those for acute myeloid leukemia. Much work remains to be accomplished as myeloid sarcomas, if initially missed or misdiagnosed, have poor overall survival rates. Furthermore, prognostic factors for this malignancy remain poorly understood.