Rapid progression from MDS to AML with gastric submucosal tumour as an extramedullary infiltration.

We present a rare case of myeloid sarcoma in the stomach of an elderly woman initially diagnosed with anaemia. Myeloid sarcoma, an unusual extramedullary manifestation of acute myeloid leukaemia (AML), primarily affects lymph nodes, bones, spine and skin, with gastrointestinal involvement being infrequent. Despite normal results from the initial endoscopy, a follow-up examination after 4 months revealed multiple submucosal gastric tumours. These developments coincided with worsening of anaemia and an increase in peripheral myeloblasts. Pathological evaluation and immunohistochemical staining confirmed gastric extramedullary infiltration associated with AML. This case highlights the importance of comprehensive diagnostic processes when suspecting leukaemic transformations, especially in myelodysplastic syndrome (MDS). Due to financial constraints, additional critical studies such as cytogenetics and next-generation sequencing were not performed. Nonetheless, this rare case demonstrates the visual observation of rapid progression from MDS to AML and concurrent early myeloid sarcoma development in an elderly patient.

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.

18 F-FDG PET/CT Imaging of Isolated Myeloid Sarcoma in the Right Humerus.

ABSTRACT: Myeloid sarcoma is a neoplastic mass formed by the infiltration of primitive or immature myeloid cells into organs and tissues outside the bone marrow. It may occur before, at the same time, or manifest as the recurrence of acute myeloid leukemia, myelodysplastic syndromes, and chronic myeloproliferative syndromes. It may involve any organ or tissue, including skin, soft tissue, lymph nodes, and gastrointestinal tract and bone. Isolated humerus involvement is extremely rare. Herein, we present the FDG PET/CT findings of a rare case of isolate myeloid sarcoma in the right humerus, which showed only increased bone density with moderate FDG uptake.

Nasopharyngeal myeloid sarcoma as a manifestation of acute monomyelocytic leukaemia.

This case report describes the case of a man in his seventies presenting with a nasopharyngeal deposit of myeloid sarcoma associated with acute monomyelocytic leukaemia. He presented with right nasal obstruction associated with unilateral pulsatile tinnitus. CT and MRI scans of sinuses identified a moderately restricting mucosal swelling of the right torus tubarius, and a biopsy of the lesion diagnosed a nasal deposit of myeloid sarcoma.

Myeloid sarcoma and pathological fracture: a case report and review of literature.

Myeloid sarcoma is a rare clinical entity that presents as an isolated proliferation of leukemic cells, concurrently with or at relapse of acute myeloid leukemia (AML), myelodysplastic syndromes/neoplasms (MDS), chronic myeloid leukemia (CML), and myeloproliferative neoplasm (MPN). Myeloid sarcoma disrupts the normal architecture of its surrounding tissues. When it forms in long bones, it can cause their pathological fracture. We recently experienced a rare case of MDS presenting with myeloid sarcoma in the femur that eventually resulted in its pathological fracture. Detailed chromosomal analysis of the bone marrow cells suggested emergence of myeloid sarcoma during the fast-paced progression of MDS just after acquiring trisomy 22. A comprehensive review of previous cases of myeloid sarcoma-associated pathological fracture indicated possible involvement of structural rearrangements of chromosomes 9 and 22. Management of myeloid sarcoma should continue to improve, and clinicians should note that myeloid sarcoma with specific chromosomal alterations needs extra medical attention to prevent pathological fracture.

Myeloid sarcoma incidentally found in lymph nodes dissected for advanced gastric cancer.

Myeloid sarcoma (MS) is a condition characterized by a tumor mass of myeloid blasts in any site of the body other than the bone marrow, with or without acute myeloid leukemia. A 93-year-old man underwent laparoscopy-assisted distal gastrectomy with D1 lymphadenectomy for advanced gastric cancer. Other than metastatic foci of gastric cancer cells, some dissected lymph nodes showed destructive architecture with proliferation of small- to medium-sized atypical hematopoietic cells. Those cells were focally positive for naphthol AS-D chloroacetate esterase. Immunohistochemically, positive results were obtained for CD4, CD33, CD68 (KP1), Iba-1, lysozyme, myeloperoxidase, and PU.1, with focally positive results for CD13, CD14, CD68 (PGM1), CD163, and CD204, and negative results for AE1/AE3, CD1a, CD3, CD20, and S-100 protein. These results suggested MS with phenotypically myelomonocytic differentiation. We report a rare case of MS incidentally found in specimens resected for other purposes. Careful diagnosis and consideration of differential diagnoses including MS using an adequate panel of antibody markers for dissected lymph nodes is warranted.

Myeloid sarcoma in a newborn: A rare manifestation of congenital acute myeloid leukemia.

Cutaneous myeloid sarcoma is rarely present prior to the diagnosis of congenital acute myeloid leukemia (AML); the former is typically diagnosed with or after the leukemia. We report a 2-day-old male born with multiple cutaneous red to violaceous nodules. Histopathologic and immunohistochemistry findings from a skin nodule were suspicious for myeloid sarcoma. Bone marrow biopsy was initially negative for aberrant blasts; however, at age 4 months, AML with a KMT2A gene rearrangement was identified via bone marrow biopsy.

Myeloid sarcoma with NPM1 mutation may be clinically and genetically distinct from AML with NPM1 mutation: a study from the Bone Marrow Pathology Group.

Myeloid sarcoma (MS) is currently considered equivalent to de novo acute myeloid leukemia (AML); however, the relationship between these entities is poorly understood. This retrospective multi-institutional cohort study compared 43 MS with NPM1 mutation to 106 AML with NPM1 mutation. Compared to AML, MS had more frequent cytogenetic abnormalities including complex karyotype (p = .009 and p = .007, respectively) and was enriched in mutations of genes involved in histone modification, including ASXL1 (p = .007 and p = .008, respectively). AML harbored a higher average number of gene mutations (p = .002) including more frequent PTPN11 mutations (p < .001) and mutations of DNA-methylating genes including DNMT3A and IDH1 (both p < .001). MS had significantly shorter overall survival (OS) than AML (median OS: 44.9 vs. 93.2 months, respectively, p = .037). MS with NPM1 mutation has a unique genetic landscape, and poorer OS, compared to AML with NPM1 mutation.

First study comparing genetic profiles of MS and AML with a common disease-defining lesion.NPM1^Mut MS may be genetically distinct from NPM1^Mut AML.NPM1^Mut MS may have inferior overall survival compared to NPM1^Mut AML.

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.

Malignant Progression of an Ancestral Bone Marrow Clone Harboring a CIC-NUTM2A Fusion in Isolated Myeloid Sarcoma.

Myeloid sarcoma is a rare condition consisting of extramedullary myeloid blasts found in association with acute myeloid leukemia or, in the absence of bone marrow involvement. We identified an infant with isolated myeloid sarcoma whose bone marrow was negative for involvement by flow cytometry. Sequencing revealed the fusion oncogene CIC-NUTM2A and identified the sarcoma to be clonally evolved from the bone marrow, which carried the fusion despite the absence of pathology. Murine modeling confirmed the ability of the fusion to transform hematopoietic cells and identified receptor tyrosine kinase (RTK) signaling activation consistent with disruption of the CIC transcriptional repressor. These findings extend the definition of CIC-rearranged malignancies to include hematologic disease, provide insight into the mechanism of oncogenesis, and demonstrate the importance of molecular analysis and tracking of bone marrow involvement over the course of treatment in myeloid sarcoma, including patients that lack flow cytometric evidence of leukemia at diagnosis. IMPLICATIONS: This study illustrates molecular involvement of phenotypically normal bone marrow in myeloid sarcoma, which has significant implications in clinical care. Further, it extends the definition of CIC-rearrangements to include hematologic malignancies and shows evidence of RTK activation that may be exploited therapeutically in cancer(s) driven by these fusions.

Myeloid Sarcoma of the Breast as Blast Phase of JAK2-Mutated (Val617Phe Exon 14p) Essential Thrombocythemia: A Case Report and a Systematic Literature Review.

INTRODUCTION: Myeloid sarcoma (MS) is a mass-forming proliferation of myeloid blasts. Frequently, it arises as blast phase of pre-existing myeloproliferative, myelodysplastic disorders or consequent to bone marrow transplant. Its molecular characterization has become an increasingly important requirement for the diagnostic definition of this solid leukemia. CASE PRESENTATION: Our case report concerns an MS arising in the breast of a woman with a previous diagnosis of JAK2-mutated essential thrombocythemia (Val617Phe exon 14p) mimicking, on histology, a lobular carcinoma of the breast. The immunohistochemical study of the neoplasm provided the key that solved the diagnostic doubt and the immunohistochemical evaluation of NPM protein expression, which turn out to be negative, provided a clear indication on the molecular status and prognosis of the disease. A year later, the neoplasm relapsed in the pelvic area. DISCUSSION: This diagnostic challenge led us to review the literature of the past 10 years concerning MS of the breast. To the best of our knowledge, this was the first case of MS of the breast occurring in a patient with a history of essential thrombocythemia and recurred in the pelvic region.

18 F-FDG PET/CT Findings of Myeloid Sarcoma Involving the Left Ventricle and Kidney in a Pediatric Patient.

ABSTRACT: A 1-year-old girl presented with vomiting for 1 week. Abdominal ultrasound revealed a mass with increased blood flow in the left lower abdomen. A malignancy was suspected. 18 F-FDG PET/CT showed multiple lesions in the left ventricular wall, the kidney, and the left lower abdomen. Biopsy of the left abdominal mass confirmed the diagnosis of myeloid sarcoma associated with acute myeloid leukemia. After 4 cycles of chemotherapy, follow-up PET/CT was performed for evaluating the therapy response, which showed complete resolution.

Isolated pancreatic myeloid sarcoma: A potential mimicker of pancreatic adenocarcinoma.

Myeloid sarcoma (MS) is an extramedullary proliferation of immature myeloid cells which may occur as a progression of myelodysplastic syndrome (MDS), myeloproliferative neoplasm (MPN), or myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) and as acute myeloid leukemia (AML) relapse. Rarely may it be de novo. Lymph nodes, skin, lungs, intestine are the commonly involved sites. However, an isolated pancreatic MS is seldom reported in the literature. Herein, we report one such case which was misdiagnosed as pancreatic adenocarcinoma on the clinico-radiological examination which misled us away from preoperative diagnostic sampling, and a Whipple pancreaticoduodenectomy was performed. Histopathological examination in conjunction with immunohistochemistry revealed the final diagnosis of isolated MS of the pancreas. We emphasize that although rare, a clinical suspicion along with preoperative histopathological examination may lead to early diagnosis, targeted management, and a better clinical outcome in such cases.

Unusual presentations of central nervous system myeloid sarcoma.

Myeloid sarcoma (MS), also termed 'chloroma' or 'granulocytic sarcoma', is a tumour mass consisting of myeloid blasts occurring at an anatomical site other than the bone marrow. MS occurs in up to 8% of patients with acute myeloid leukaemia. While MS typically involves the skin or lymph nodes, almost any tissue can be affected, and symptoms largely depend on the organ involved and subsequent mass effect. We present a case series of patients that presented to a tertiary hospital with MS affecting the central nervous system over a 4-month period. These three cases demonstrate the vast spectrum of clinical presentations of MS and, furthermore, show rare examples of intramedullary spinal cord involvement and disseminated intraparenchymal brain disease.

Testicular myeloid sarcoma: a relapse of acute myeloid leukaemia after allogeneic peripheral blood stem cell transplantation- a rare presentation.

Myeloid sarcoma is an uncommon pathological diagnosis of proliferation of blasts of one or more of the myeloid lineages in regions other than the blood and bone marrow. Myeloid sarcoma of the testis after allogeneic bone marrow stem cell transplantation is very rare and only few cases are reported in the literature. It is usually misdiagnosed as malignant lymphoma, particularly with large cell lymphoma, due to similar histological morphology. Due to difficulty in diagnosis, it is suggested that an appropriate panel of immunohistochemical marker studies be performed in conjunction with clinical correlation to avoid misleading diagnosis and improper treatment of patients. We report an interesting case of a 49-year-old man with a diagnosis of acute myelogenous leukaemia. He had undergone allogeneic peripheral blood stem cell transplantation, achieved complete molecular remission and later relapsed with myeloid sarcoma of the testis.

Intraoral myeloid sarcoma presenting as toothache and gingival mass.

A female patient in her 70s with a medical history of myelodysplastic neoplasm presented to the outpatient department with a 4-month history of toothache, painful gingival swelling and loose teeth that required extractions. Intraoral examination revealed a swelling in the lower anterior portion of the mandible, which displaced her teeth. Incisional biopsy of the gingival lesion revealed dense aggregates of atypical round cells which stained positive for CD43, CD45, CD33 and myeloperoxidase, consistent with myeloid sarcoma. Subsequent bone marrow biopsy displayed hypercellular marrow with immature myeloid elements and 21% myeloblasts by flow cytometry, compatible with diagnosis of acute myeloid leukaemia (AML). The patient initially went into remission after treatment but later died of AML relapse after 18 months.

Clinicopathological analysis of myeloid sarcoma with megakaryocytic differentiation.

Myeloid sarcoma (MS) is defined as a tumour mass consisting of myeloid blasts that occurs at an anatomical site other than bone marrow. MS with megakaryocytic differentiation (MSmgk) is extremely rare and its clinicopathological features have not been well described. We reviewed 11 cases in 11 patients of extramedullary mass-forming malignant tumours composed of immature non-lymphoid haematopoietic cells expressing CD41 with or without concurrent bone marrow lesions. The patients consisted of seven men and four women (1.75:1 male-to-female ratio). The mean and median ages at diagnosis were 50 and 62 years, respectively, ranging from 2 to 78 years. Extramedullary mass lesions were solitary in three cases (27%) and multiple in eight cases (73%). Tumour locations were lymph nodes (6 cases), subcutaneous tissue (3 cases), intramuscular (1 case), and bone (1 case). Seven of the 11 patients (64%) had a history of myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN). Three patients (27%) developed MS during remissions of acute myelogenous leukaemia, and one patient had a recurrence of MS at other sites. Follow-up data were available for four cases. Tumour cells were positive for CD41, CD33, CD34, MPO, and CD68 in 11 (100%), three (27%), seven (64%), four (36%), and seven (64%) cases, respectively. Cytogenetic analysis was successfully performed in two cases. Complex but inconsistent abnormalities were evident. When compared with cases of MS without megakaryocytic differentiation, the survival of MSmgk was significantly shorter (p=0.0033). Compared to MS without megakaryocytic differentiation, MSmgk is more likely to follow MDS/MPN, to involve multiple sites, and to be associated with poorer outcomes. More detailed studies, including genomic or gene expression analyses, could confirm the characteristics of MSmgk.

Granulocytic sarcoma causing long spinal cord compression: Case report and literature review.

Context: Granulocytic sarcoma (GS) is an extramedullary form of proliferating myeloblasts. It is frequently reported in patients with acute myeloid leukemia (AML) but rarely in patients with chronic myeloid leukemia (CML). Spinal cord compression caused by CML-associated GS is exceedingly rare, with only few cases reported in the literature. To our knowledge, this is the first reported case in which GS caused such extensive compression.Findings: A 37-year-old man with CML suffered from back pain for 2 months. Notably, he had already achieved molecular remission (MR) after receiving imatinib mesylate for CML; bone marrow aspiration results were consistent with CML in chronic phase. Image examination revealed that developed GS occupied nearly the entire thoracic spinal canal, thereby causing extensive spinal cord compression. The tumor completely diminished after his treatment regimen was upgraded. He showed no signs of recurrence after 1-year follow-up.Conclusion: Extramedullary infiltration of CML should be taken into consideration when a mass lesion develops and compresses the spinal cord in a CML patient who has been receiving routine and standard treatment modalities; thus, a sudden and unexpected progression mandates a refinement and upgrade of treatment modality.