Association of immune evasion in myeloid sarcomas with disease manifestation and patients' survival.

Introduction: Myeloid sarcomas (MS) comprise rare extramedullary manifestations of myeloid neoplasms with poor patients' outcome. While the clinical relevance of the tumor microenvironment (TME) is well established in many malignancies, there exists limited information in MS. Methods: The expression of the human leukocyte antigen class I (HLA-I) antigens, HLA-I antigen processing and presenting machinery (APM) components and the composition of the TME of 45 MS and paired bone marrow (BM) samples from two independent cohorts were assessed by immunohistochemistry, multispectral imaging, and RNA sequencing (RNAseq). Results: A significant downregulation of the HLA-I heavy chain (HC; 67.5%) and ß2-microglobulin (ß2M; 64.8%), but an upregulation of HLA-G was found in MS compared to BM samples, which was confirmed in a publicly available dataset. Moreover, MS tumors showed a predominantly immune cell excluded TME with decreased numbers of tissue infiltrating lymphocytes (TILs) (9.5%) compared to paired BM (22.9%). RNAseq analysis of a subset of 10 MS patients with preserved and reduced HLA-I HC expression revealed 150 differentially expressed genes and a significantly reduced expression of inflammatory response genes was found in samples with preserved HLA-I expression. Furthermore, low HLA-I expression and low TIL numbers in the TME of MS cases were linked to an inferior patients' outcome. Discussion: This study demonstrated a high prevalence of immune escape strategies in the pathogenesis and extramedullary spread of MS, which was also found in patients without evidence of any BM pathology, which yields the rational for the development of novel individually tailored therapies for MS patients.

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.

Myeloid sarcoma in JAK2-positive myelodysplastic neoplasms with fibrosis: a case report and literature review.

Myeloid sarcoma (MS) occurs in patients with acute myeloid leukemia (AML). In rare cases, MS can represent a form of blast transformation in patients with myeloproliferative neoplasms (MPN), myelodysplastic neoplasms (MDS), or MDS/MPN. The most frequent chromosomal alterations in MS are t(8;21) or inv(16), with other alterations being reported. Cases of MS in Janus kinase 2 (JAK2)-positive MDS with fibrosis are exceedingly rare. Here, we describe such a case. To the best of our knowledge, this is the first report of a JAK2 V617F mutation-positive MDS case occurring concurrently with MS involving the posterior aspect of the left seventh rib. No clear association has been previously demonstrated between the intramedullary AML cytogenetics and extramedullary disease occurrence. Interestingly, samples from the intramedullary MDS and extramedullary mass in this patient presented the same JAK2 V617F mutation. Following a treatment regimen of azacitidine and venetoclax, the patient achieved complete remission. The chest CT scan showed that the seventh posterior rib mass disappeared. This case provides valuable information for the potential future treatment of this disease.

Atypical Presentation of Acute Suppurative Otitis Media with Facial Palsy: Extra Medullary Manifestation of AML in Temporal Bone.

Acute Myeloid Leukemia (AML) is the most common leukemia observed in the adult population, accounting for 80% of all leukemia cases. Extramedullary involvement in AML, where leukemic cells are found in organs or tissues outside the blood or bone marrow, is a rare occurrence [1]. The most frequent sites of extramedullary disease include the skin, central nervous system (CNS), and lymph nodes [2, 3]. In this case report, we present an instance of extramedullary AML in the temporal bone, which initially presented with symptoms such as earache, discharge, and facial asymmetry, mimicking acute suppurative otitis media with facial palsy. The patient underwent mastoid exploration and facial nerve decompression. A post-operative bone marrow biopsy confirmed the diagnosis of AML, leading to the initiation of chemotherapy. The patient is currently under follow-up care.

Myeloid sarcoma with maxillary gingival swelling as the initial symptom: A case report and review of literature.

BACKGROUND: Myeloid sarcoma (MS), also referred to as granulocytic sarcoma or chloroma, is a rare type of extramedullary malignant tumor. MS comprises primitive granulocytic precursor cells that play a key role in the early stages of white blood cell development. Notably, the occurrence of this tumor in the gingiva is rare. CASE SUMMARY: The present study reported the case of MS with gingival swelling in the maxillary region, with aleukemic presentation in a 32-year-old male patient. Following two courses of chemotherapy, computed tomography of the region demonstrated complete clearance of the tumor. At the 12-month follow-up appointment, the patient was in a stable condition with the absence of progression. The etiology, clinical features, diagnosis, and relevant treatment of MS are discussed in the present study. CONCLUSION: Diagnosis of MS may be confirmed following histological and immunohistochemical examinations.

Myeloid Sarcoma of the Colon Initially Presenting as a Paracolic Abscess in a Patient with Relapsed Acute Myeloid Leukemia.

Myeloid sarcoma, a rare extramedullary manifestation of acute myeloid leukemia (AML), can occur in various anatomic sites but seldom involves the gastrointestinal tract. We report the unusual case of a 49-year-old man with a history of AML who initially presented with abdominal pain and imaging findings suggestive of a paracolic abscess. However, the lesion rapidly progressed to a large descending colon mass with peritoneal involvement over five weeks. Surgical resection and histopathological examination confirmed a diagnosis of myeloid sarcoma. This case highlights the potential of myeloid sarcoma to mimic an inflammatory colonic process at initial presentation prior to manifesting as an overt mass lesion. Although exceedingly rare, myeloid sarcoma should be considered in patients with a history of AML presenting with colon lesions, particularly in those with an aggressive clinical course. Early recognition may expedite appropriate treatment and prevent unnecessary procedures. This report also underscores the importance of correlating imaging findings with clinical history and histopathology findings to establish an accurate diagnosis.

Case report: Clinical features of pediatric acute myeloid leukemia presenting with cardiac tamponade: a case series study and literature review.

Objective: This study aims to elucidate the clinical features observed in cases of pediatric acute myeloid leukemia (AML) initially presenting with cardiac tamponade and to share treatment experiences. Materials and methods: Five pediatric patients were initially diagnosed with AML accompanied by cardiac myeloid sarcoma (MS). The diagnosis was established by examining our hospital records and reviewing pertinent literature from 1990 to July 2023, accessible through MEDLINE/PubMed. We comprehensively assessed the clinical characteristics and treatment modalities employed for these patients. Result: Five pediatric patients presented with acute symptoms, including shortness of breath, malaise, cough, and fever, leading to their hospitalization. Physical examination revealed irritability, hypoxia, tachypnea, tachycardia, and hypotension. Initial detection utilized chest X-ray or echocardiogram, leading to subsequent diagnoses based on pericardial effusion and/or bone marrow examination. Two patients received chemotherapy at the time of initial diagnosis, one with cytarabine and etoposide, and the other with cytarabine and cladribine. Post-treatment, their bone marrow achieved remission, and over a 2.5-year follow-up, their cardiac function remained favorable. Unfortunately, the remaining three patients succumbed within two weeks after diagnosis, either due to receiving alternative drugs or without undergoing chemotherapy. Conclusion: This is the first and largest case series of pediatric AML patients with cardiac MS, manifesting initially with cardiac tamponade. It highlights the rarity and high mortality associated with this condition. The critical factors for reducing mortality include identifying clinical manifestations, conducting thorough physical examinations, performing echocardiography promptly, initiating early and timely pericardial drainage, and avoiding cardiotoxic chemotherapy medications.

Granulocytic neoplasm suggestive of primary myeloid sarcoma in 3 dogs.

Myeloid sarcoma (MS) is a solid tumor of granulocytic origin with extramedullary localization. This tumor is rare in humans and animals. The diagnostic approach is heterogeneous, and the definitive diagnosis may be difficult to achieve. Primary MS has never been described as a spontaneous neoplasm in companion dogs. Two purebred and 1 mixed-breed dogs, 6- to 11-year-old, developed round cell tumors in the mediastinum, lymph nodes (LNs) and tonsils, and LNs, respectively. Granulocytic origin and exclusion of lymphoid lineage were confirmed by flow cytometry, supported by immunohistochemistry or immunocytochemistry. Pivotal to the diagnosis were positive labeling for myeloid (CD11b, CD14) and hematopoietic precursors (CD34) markers, along with negative labeling for lymphoid markers. Blood and bone marrow infiltration were not detected at initial diagnosis, excluding acute myeloid leukemia. The behavior of these tumors was aggressive, resulting in poor clinical outcomes, even when chemotherapy was attempted.

Real-world experience with venetoclax-based therapy for patients with myeloid sarcoma.

BACKGROUND: The treatment of myeloid sarcoma (MS) is challenging and has not markedly improved patient prognosis. The introduction of venetoclax (VEN) has changed the treatment of MS, and venetoclax-based therapy has been described as very promising in several case reports. METHODS: In this retrospective study, we analyzed the treatment outcomes of 14 patients with MS treated with venetoclax-based therapy at The First Affiliated Hospital of Xiamen University from January 2020 to October 2023 RESULTS: The cohort consisted of 7 (50%) women and 7 (50%) men with an average age of 37.5 years. Four patients (28.6%) had isolated MS de novo, 2 (14.2%) were diagnosed synchronously with AML, and 8 (57.2%) had isolated extramedullary relapse. The most common sites for MS in our cohort were the skin and lung, followed by the spinal canal, soft tissue, bone and kidney. Five patients were affected at more than three sites. Nine patients received VEN in combination with azacytidine, and 5 patients received VEN in combination with other agents. The median number of venetoclax therapies administered was 2 cycles (range: 1-10 cycles). A response was observed in all patients included in the study, with 8 patients (57.2%) achieving a CR and 3 patients (21.4%) achieving a PR, corresponding to an ORR (including CR and PR) of 78.6%. The median follow-up time for all patients was 13 months (range 1-44 months), and the 1 year OS for all patients was 67.7%. CONCLUSIONS: Venetoclax-based therapy shows excellent efficacy and safety in MS patients in the "real world" at a single institution, and a corresponding prospective study is needed to verify this conclusion.

Spinal myeloid sarcoma presenting as initial symptom in acute promyelocytic leukemia with a rare cryptic PLZF::RARα fusion gene: a case report and literature review.

Background: Acute promyelocytic leukemia (APL) is rarely caused by the PLZF::RARα fusion gene. While APL patients with PLZF::RARα fusion commonly exhibit diverse hematologic symptoms, the presentation of myeloid sarcoma (MS) as an initial manifestation is infrequent. Case presentation: A 61-year-old patient was referred to our hospital with 6-month history of low back pain and difficulty walking. Before this admission, spine magnetic resonance imaging (MRI) conducted at another hospital revealed multiple abnormal signals in the left iliac bone and vertebral bodies spanning the thoracic (T11-T12), lumbar (L1-L4), and sacral (S1/S3) regions. This led to a provisional diagnosis of bone tumors with an unknown cause. On admission, complete blood count (CBC) test and peripheral blood smear revealed a slightly increased counts of monocytes. Immunohistochemical staining of both spinal and bone marrow (BM) biopsy revealed positive expression for CD117, myeloperoxidase (MPO), and lysozyme. BM aspirate showed a significant elevation in the percentage of promyelocytes (21%), which were morphologically characterized by round nuclei and hypergranular cytoplasm. Multiparameter flow cytometry of BM aspirate revealed that blasts were positive for CD13, CD33, CD117, and MPO. Through the integrated application of chromosome analysis, fluorescence in situ hybridization (FISH), reverse transcriptase polymerase chain reaction (RT-PCR), and Sanger sequencing, it was determined that the patient possessed a normal karyotype and a rare cryptic PLZF::RARα fusion gene, confirming the diagnosis of APL. Conclusion: In the present study, we report the clinical features and outcome of a rare APL patient characterized by a cryptic PLZF::RARα fusion and spinal myeloid sarcoma (MS) as the initial presenting symptom. Our study not only offers valuable insights into the heterogeneity of APL clinical manifestations but also emphasizes the crucial need to promptly consider the potential link between APL and MS for ensuring a timely diagnosis and personalized treatments.

Myeloid sarcoma with plasmacytoid dendritic cell-like proliferation associated with IKZF1, ETV6 and DNMT3A mutations.

The classification of clonal plasmacytoid dendritic cell (pDC) proliferation associated with myeloid neoplasms remains a topic of ongoing debate. Although the fifth edition of the World Health Organization classification classifies clonal pDC proliferation into two categories, it is unclear whether this classification adequately captures the complexities of clonal pDC pathogenesis. We present a clinical case featuring myeloid sarcoma with pDC-like cells in cervical lymph nodes and bone marrow (BM). Analysis of biopsy specimens and BM aspirate revealed two distinct cellular populations expressing myeloid and pDC markers. One population exhibited myeloid leukemia and monocyte markers, including MPO, CD13, CD33, CD11b, and CD14, while the other manifested an immunophenotype reminiscent of pDCs, characterized by expression of CD56 and CD123. Additionally, whole exome sequencing and RNA sequencing of BM mononuclear cells were conducted to explore the pathophysiology of this rare malignancy, and unveiled pDC-like cell proliferation driven by IKZF1 and ETV6 mutations originating from clonal hematopoiesis initiated by a DNMT3A mutation. Notably, venetoclax-based therapy exhibited efficacy for achieving and sustaining complete remission. This case provides pivotal insights into the mechanistic aspects of pDC/pDC-like cell proliferation in myeloid sarcoma, offering valuable perspectives on therapeutic strategies.

Osteolytic lesions as a presenting sign of acute myeloid leukemia: a case report.

Osteolytic lesions are infrequently observed in adult patients with acute myeloid leukemia (AML). This report details the case of a 66-year-old male patient who presented with myeloid sarcoma (MS), osteolytic lesion and pancytopenia. Effective treatments were delayed due to diagnostic challenges and the rapid progression of the disease. It is essential to consider AML in the differential diagnosis when faced with a patient presenting osteolytic lesions and pancytopenia.

Lymph node myeloid sarcoma with TP53­associated myelodysplastic syndrome: A case report.

Myeloid sarcoma (MS) is a rare extramedullary tumor mass that carries a high risk of progression to acute myeloid leukemia (AML), and patients with MS are commonly treated with the AML regimen. However, MS is frequently misdiagnosed due to its lack of clinical specificity. Patients with MS who harbor tumor protein p53 (TP53) mutations and complex karyotypes are considered to have a poorer prognosis. The present study reports a case of lymph node MS with TP53 (V173G)-related myelodysplastic syndrome (MDS). The mass was first considered to be a lymphoma and treated as such. However, following immunohistochemical analysis, which revealed cells positive for CD43, myeloperoxidase and CD117, the patient was later diagnosed with MS combined with MDS. The patient went into complete remission after the first cycle of chemotherapy, and showed a decrease in platelet, red blood cell and white blood cell counts following the second cycle of chemotherapy. After the third chemotherapy, agranulocytosis occurred, leading to refractory pneumonia and eventually death due to respiratory failure. MS with TP53-related MDS has a low incidence rate, a poor prognosis and a short survival time. The clinical manifestations of MS are non-specific and easy to misdiagnose, leading to delayed diagnosis and treatment, and ultimately worsening the prognosis of the patients. Therefore, a lymph node biopsy should be performed as soon as possible for patients with lymph node enlargement, and early treatment should be carried out to prolong the survival period.

Chameleonic Chloroma: A Case of Myeloid Sarcoma Presenting as a Pancreatic Head Mass.

We report a case of pancreatic myeloid sarcoma (MS), an extremely rare manifestation of acute myeloid leukemia (AML), in a 35-year-old male who presented with epigastric pain and watery stools. Initial diagnostic testing was inconclusive; however, following an extensive evaluation, endoscopic biopsies suggested AML, which was confirmed by a bone marrow biopsy. Given that few cases are documented in the literature, pancreatic MS without a preexisting hematologic malignancy poses a significant diagnostic challenge.

First Case of FLT3-Tyrosine Kinase Domain Mutant Acute Myeloid Leukemia With Unusual Onset as Isolated Bilateral Testicular Myeloid Sarcoma.

Testicular myeloid sarcoma (TMS) is a challenging pathology often posing diagnostic difficulties due to the poorly differentiated nature of tumor cells at the initial presentation. The delay in diagnosis significantly impacts patient life expectancy, emphasizing the need for prompt identification and treatment initiation. In certain cases, the presence of the Fms-like tyrosine kinase (FLT3) mutation adds complexity to the disease, requiring tailored therapeutic approaches. In this report, we present a unique case of bilateral TMS with FLT3 tyrosine kinase domain (TKD) mutation. The patient exhibited an aggressive clinical course, initially misdiagnosed with orchitis during the initial evaluation. Subsequent reevaluation of the testicular biopsy at a second center led to an accurate diagnosis, highlighting the importance of thorough examination in challenging cases. Given the emerging significance of FLT3 mutations in myeloid sarcomas, comprehensive testing for all FLT3 variants is crucial to determine the appropriate treatment modality. This case underscores the need for increased awareness among healthcare professionals regarding the diagnostic nuances and potential genetic variations associated with TMS. Furthermore, the inclusion of tyrosine kinase inhibitors, such as midostaurin or gilteritinib, especially in the presence of FLT3 mutations, may significantly impact treatment outcomes. This report contributes to the growing body of literature on TMS and highlights the importance of considering FLT3 mutations in the diagnostic and therapeutic decision-making process for improved patient care.

Pediatric Myeloid Sarcoma of the Testes Treated With Surgery and Adjuvant Radiation Therapy.

Myeloid sarcoma (MS) is a rare extramedullary tumor of immature granulocytic cells and is most often associated with acute myeloid leukemia (AML). Myeloid sarcomas can occur anywhere in the body but are seldom present in the testicles, especially in the pediatric population. The treatment of MS, especially testicular myeloid sarcoma (TMS) is not well defined in the literature and the role of radiation therapy in the treatment of TMS is even less well defined. In this case report, we discuss the treatment for TMS in a pediatric patient, review the literature, and discuss the role of radiation therapy in the treatment.

Gastric myeloid sarcoma mimicking pseudoachalasia in non-leukemic context: a singular case report.

Introduction and importance: Myeloid sarcoma (MS) is a rare tumour associated with acute myeloid leukaemia (AML) and occasionally occurs independently. It typically affects skin, bone, lymph nodes, and rarely the gastrointestinal tract, with gastric cases being extremely rare. Notably, no reported instances associate pseudoachalasia with gastric myeloid sarcoma. Case presentation: A 20-year-old male presented with severe dysphagia, refractory vomiting, and weight loss. Diagnosed with type III achalasia via oesophageal tests, subsequent gastroscopy revealed a large gastric mass, later identified as gastric myeloid sarcoma through histopathology. Clinical discussion: MS, characterized by immature blast cells, poses diagnostic challenges without typical leukaemia symptoms. Diagnosis involves immunohistochemistry, employing markers like CD33, CD34, and CD43. Optimal treatments, such as chemotherapy or stem cell transplantation, aim to delay leukaemia progression. Gastric primary de-novo myeloid sarcoma is exceedingly rare, emphasizing the need for tailored treatment strategies. Conclusion: Gastric myeloid sarcoma is an exceptionally rare tumour, especially without concurrent acute myeloid leukaemia (AML), complicating its diagnosis. This case represents the first globally documented instance of gastric myeloid sarcoma causing pseudoachalasia. Documenting this unique clinical presentation is crucial for a better grasp of gastric myeloid sarcoma's diverse manifestations.

An isolated sacral promyelocytic sarcoma in a child: A rare case report with emphasis on cytomorphology.

Myeloid sarcoma (MS) is an uncommon localized extramedullary tumor composed of immature myeloid precursor cells that can affect any organ. Promyelocytic sarcoma (PS), an extremely rare subtype of MS, is characterized by immature myeloid cells with features of acute promyelocytic leukemia (APL). We describe a case of pediatric PS that presented as a solitary sacral mass without any evidence of systemic or bone marrow involvement. The cytopathologic evaluation using touch imprint demonstrated numerous blasts with bilobed nuclei, cytoplasmic hyper-granularity, and aggregates of Auer rods, which are typical cytomorphologic features of APL. Herein, we report an extremely rare case of isolated PS in a child, emphasizing the importance of cytomorphologic evaluation, which is complemented by the findings from a comprehensive work-up.