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.

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.

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.

Pancreatic Myeloid Sarcoma Causing Obstructive Jaundice: A Case Report and Literature Review

Myeloid sarcoma (MS) is an extramedullary manifestation of acute myeloid leukemia (AML) and commonly occurs in sites such as the lymph nodes, skin, soft tissues, and bone. It more rarely manifests in the pancreas, with less than 20 cases reported in the literature since 1987. Despite its rarity, MS should be considered in the differential diagnosis of a soft tissue mass causing obstructive jaundice, especially if the patient has a known hematologic disease. Isolated cases of pancreatic MS have been known to progress to AML; therefore, it is crucial to differentiate MS from more common diagnoses, such as pancreatic cancer or pancreatitis. This is a case of a 70-year-old male with symptomatic obstructive jaundice secondary to pancreatic MS, ultimately requiring endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) for diagnosis and management. Also included is a comprehensive review of previous case reports with similar clinical presentations, management, and treatment of pancreatic MS.

Magnetic resonance imaging in paediatric ocular and orbital lesions: A pictorial review

Paediatric orbital lesions encompass a wide spectrum of benign and malignant entities that can arise from different components of the orbit. Clinical symptoms and signs are often nonspecific, and imaging plays a crucial role in the diagnosis and management. Ultrasonography has a limited role and radiation is a major concern with CT especially in the paediatric population. MRI is the modality of choice that avoids the radiation hazard and provides superior soft tissue contrast. The lesions can be localized using the 'compartment' approach which helps to narrow the list of differentials. MRI also provides critical information for management such as presence of perineural spread and intracranial extension. This article depicts the spectrum of Magnetic Resonance imaging findings encountered in paediatric ocular and orbital lesions.

Clinical characteristics, treatment options, and prognosis of myeloid sarcoma: analysis using the SEER database

BACKGROUND

Myeloid sarcoma (MS) is a very rare hematologic disorder. This study analyzes the early treatment options for patients with different types of MS and explores the prognostic factors of MS.

METHODS

Patients aged 15 years and older with MS in the SEER database (diagnosed from 2000 to 2018) were selected, excluding those with an unknown first course of treatment, an unknown location of disease, and less than 1 month of follow-up. Statistical methods used a chi-square test to compare clinical characteristics; Kaplan-Meier analysis to compare survival differences; and Cox proportional risk models to identify prognostic factors affecting overall survival (OS).

RESULTS

Data were collected from 472 patients: 244 patients with isolated myeloid sarcoma (IMS) and 228 patients with non-isolated myeloid sarcoma (non-IMS). IMS patients mostly chose local treatment, while non-IMS patients mostly chose chemotherapy. There was a significant difference in OS between IMS patients treated with combined treatment and those without treatment. For non-IMS, treated patients had longer OS than untreated, but the difference was not statistically significant. Among adult patients, those younger than 60 years had a better prognosis. Patients with the urinary system, digestive system, reproductive system and chest and abdomen as the initial site had a better prognosis.

CONCLUSIONS

Early combination therapy in IMS patients had a longer OS, and chemotherapy combined with radiotherapy/surgery should be the treatment of choice. For non-IMS patients, early combination therapy did not show a significant advantage. Age and location of first presentation were independent factors affecting MS patients' long-term prognosis.

First report on establishment and characterization of the extrahepatic cholangiocarcinoma sarcoma cell line CBC2T-2

BACKGROUND

Extrahepatic cholangiocarcinoma sarcoma is extremely rare in clinical practice. These cells consist of both epithelial and mesenchymal cells. Patient-derived cell lines that maintain tumor characteristics are valuable tools for studying the molecular mechanisms associated with carcinosarcoma. However, cholangiocarcinoma sarcoma cell lines are not available in cell banks.

AIM

To establish and characterize a new extrahepatic cholangiocarcinoma sarcoma cell line, namely CBC2T-2.

METHODS

We conducted a short tandem repeat (STR) test to confirm the identity of the CBC2T-2 cell line. Furthermore, we assessed the migratory and invasive properties of the cells and performed clonogenicity assay to evaluate the ability of individual cells to form colonies. The tumorigenic potential of CBC2T-2 cells was tested in vivo using non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. The cells were injected subcutaneously and tumor formation was observed. In addition, immunohistochemical analysis was carried out to examine the expression of epithelial marker CK19 and mesenchymal marker vimentin in both CBC2T-2 cells and xenografts. The CBC2T-2 cell line was used to screen the potential therapeutic effects of various clinical agents in patients with cholangiocarcinoma sarcoma. Lastly, whole-exome sequencing was performed to identify genetic alterations and screen for somatic mutations in the CBC2T-2 cell line.

RESULTS

The STR test showed that there was no cross-contamination and the results were identical to those of the original tissue. The cells showed round or oval-shaped epithelioid cells and mesenchymal cells with spindle-shaped or elongated morphology. The cells exhibited a high proliferation ratio with a doubling time of 47.11 h. This cell line has migratory, invasive, and clonogenic abilities. The chromosomes in the CBC2T-2 cells were polyploidy, with numbers ranging from 69 to 79. The subcutaneous tumorigenic assay confirmed the in vivo tumorigenic ability of CBC2T-2 cells in NOD/SCID mice. CBC2T-2 cells and xenografts were positive for both the epithelial marker, CK19, and the mesenchymal marker, vimentin. These results suggest that CBC2T-2 cells may have both epithelial and mesenchymal characteristics. The cells were also used to screen clinical agents in patients with cholangiocarcinoma sarcoma, and a combination of paclitaxel and gemcitabine was found to be the most effective treatment option.

CONCLUSION

We established the first human cholangiocarcinoma sarcoma cell line, CBC2T-2, with stable biogenetic traits. This cell line, as a research model, has a high clinical value and would facilitate the understanding of the pathogenesis of cholangiocarcinoma sarcoma.

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.

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.

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.

Dermatological manifestations of hematologic neoplasms. Part I: secondary specific skin lesions

Cutaneous manifestations occur during the course of hematologic malignancies and precede, follow, or are late events in relation to the diagnosis. They result from paraneoplastic phenomena, tumor infiltrations, and immunosuppression resulting from the hematologic neoplasia itself or its treatment. The dermatologist must be aware of these conditions, which can help both in the diagnosis of the underlying disease and in the reduction of patient morbidity. This review (part I) addresses skin lesions associated with direct infiltration by systemic hematologic malignancies.

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.

Successful Treatment of Pediatric Acute Myeloid Leukemia Presenting with Hyperbilirubinemia Secondary to Myeloid Sarcoma: A Case Report

Myeloid sarcoma (MS), a tumor consisting of myeloid blasts with or without maturation, occurs at anatomical sites other than the bone marrow. MS of the gastrointestinal tract presenting with jaundice in children is rare. We report the case of a 4-year-old boy with a 6-week history of symptoms of obstructive jaundice due to a peripancreatic mass compressing the common bile duct. Six weeks later, blasts were found in a peripheral smear prior to surgical biopsy; bone marrow evaluation and flow cytometry results led to a diagnosis of acute myeloid leukemia (AML) with MS. No further invasive testing or temporary drainage was performed. He was started on induction therapy with full therapeutic doses of cytarabine, dose reductions of etoposide, and escalating doses of daunorubicin. His liver enzymes normalized, and he completed subsequent cycles of chemotherapy with full doses. The abdominal ultrasound showed resolution of the mass after the second cycle of chemotherapy. He is currently in remission three years after completing therapy. AML-directed chemotherapy in patients with obstructive jaundice secondary to MS may be beneficial without requiring invasive testing or temporary drainage procedures. Daily follow-up is crucial for chemotherapy dose modifications. Management plans should be individualized according to the patient’s clinical condition.

Isolated myeloid sarcoma with pericardial and pleural effusions as first manifestation: A case report

RATIONALE

Myeloid sarcoma (MS) involves the proliferation of extramedullary blasts from 1 or more myeloid lineages, replacing the original tissue structures, and these neoplasias are called granulocytic sarcoma, chloroma, or extramedullary myeloid neoplasms. These tumors develop in lymphoid organs, bones, skin, soft tissues, various mucous membranes, organs, and the central nervous system. MS is rare in non-leukemic patients, while MS patient with effusion as the first manifestation is even rare.

PATIENT CONCERNS

We report the case of 44-year-old woman with abdominal pain, diarrhea, and vomiting.

DIAGNOSIS

Ultrasound examination and computed tomography of the chest revealed large pericardial effusions and bilateral pleural effusions. Cytomorphological examination of the pericardial and pleural effusion, flow cytometry, and immunohistochemical markers suggested myeloid tumor cells. However, concurrent peripheral blood and bone marrow examinations showed no evidence of acute myeloid leukemia. The patient was eventually diagnosed with isolated MS.

INTERVENTIONS AND OUTCOMES

After chemotherapy with pirarubicin + cytarabine and high-dose cytarabine + etoposide, the pericardial effusion and pleural effusion were absorbed, and the mediastinal mass significantly shrunk. One year after patient gave up treatment, acute myeloid leukemia (AML) was confirmed by bone marrow examinations.

CONCLUSION

The early manifestations of the patient lacked specificity and were highly susceptible to misdiagnosis. Cytomorphology and flow cytology indicated important directions for the diagnosis of the disease in the early stage. Administration of chemotherapy regimen containing cytarabine could prolong disease-free survival and time before progress to AML.

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.

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.

Myeloid Sarcoma Involving the Testis in Adults: Clonal Evolution of Acute Myeloid Leukemia

To describe the clinical, histologic, immunophenotypic, and genetic characteristics of myeloid sarcoma (MS) diagnosed in the testes of adults, 3 cases were identified, and information on their presentation, clinical features, treatment, and outcome was retrieved from the medical records. In addition, histologic, immunophenotypic, and molecular characteristics were reviewed. This showed that all patients had a previous history of acute myeloid leukemia (AML), in 2 cases diagnosed >10 years before the testicular lesions. In 1 case, there was bilateral involvement, while in 2, involvement was unilateral. The neoplastic cells showed evidence of cytogenetic/molecular clonal evolution in all cases, 1 of which also had significant immunophenotypic changes. A mutational profile including NPM1 p.Trp288Cysfs*12, IDH1 p.Arg132His NRAS p.Gly12Asp was seen in 2 of the 3 cases. Concurrent bone marrow involvement by a myeloid neoplasm was diagnosed in 2 patients, in 1, there was AML in the second 8% blasts. These patients progressed rapidly after MS and had a dismal outcome. The patient with no concurrent bone marrow disease had a favorable outcome. In conclusion, MS involving the testes of adults is a rare event, and it may represent the clonal evolution of AML.

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.

Extramedullary Infiltration in Pediatric Acute Myeloid Leukemia on Surveillance Magnetic Resonance Imaging and its Relationship With Established Risk Factors

PURPOSE

Extramedullary infiltration (EMI) is a rare condition defined by the accumulation of myeloid tumor cells beyond the bone marrow. The clinical significance is still controversial. This study was aimed to evaluate the incidence, characteristics, and prognostic significance of EMI on complete magnetic resonance imaging (MRI) investigation in newly diagnosed pediatric acute myeloid leukemia (AML) patients who are asymptomatic without clinical evidence to suspect EMI.

MATERIALS AND METHODS

Retrospective clinical and radiologic review of 121 patients with MRI examination at the time of initial diagnosis of AML without any clinical evidence suggestive of EMI was performed. Patients were divided into 2 groups according to the presence or absence of EMI, and the relationship between EMI and established risk factors was analyzed. Initial white blood cell count, the occurrence of an event (including relapse, death, and primary refractory disease), survival status, and detailed information on cytogenetic/molecular status was performed by a thorough review of electronic medical records system. All patients underwent full imaging evaluation with the contrast-enhanced whole body and some regional MRI at the time of initial diagnosis.

RESULTS

The median age at diagnosis was 10.77 years (range, 0.37 to 18.83 y). Based on the risk stratification system of AML, 36, 45, and 40 patients are classified as low-risk, intermediate-risk, and high-risk groups, respectively. MRI at the time of the initial diagnosis of AML revealed 35 of 121 patients (28.9%) with EMI. The most common site of EMI was a skull, followed by the lower extremity bone and meninges of the brain. The median age at diagnosis was significantly younger in patients with EMI (7.87 vs. 11.08 y, P=0.0212). Low incidence of FLT3/ITD mutation, low incidence of AML-ETO gene rearrangement, and the larger extent and more severe degree of bone marrow involvement was related with EMI. However, there was no significant prognostic difference in event-free survival and overall survival regardless of the presence of EMI in the overall patient population and each risk group. The location of EMI occurrence was also not related to prognosis.

CONCLUSIONS

Even if EMI symptoms are not evident, surveillance MRI scans at the initial diagnosis of pediatric AML patients are very helpful in detecting a significant number of EMIs. Younger age, some molecular features, and more severe bone marrow involvement of AML patients were related with EMI. However, there was no significant prognostic difference between patients with or without EMI regardless of risk group. Further prospective investigation is necessary to validate the prognostic effect of EMI in a larger group of patients with different risk groups.

Myeloid sarcoma of uterine cervix: A case report with review of the literature

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Myeloid sarcoma of uterine cervix is very uncommon and can be the initial presentation of acute myeloid leukaemia.

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Myeloid sarcoma can mimic other malignant tumours arising in the cervix and can therefore pose a diagnostic challenge.

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Myeloid sarcoma should be considered in the differential diagnosis of undifferentiated malignant tumours arising in the gynaecological tract.

Myeloid sarcoma is a rare clinical entity, characterised by the extramedullary presence of myeloblasts. It can occur de novo or signify disease recurrence. Involvement of the female reproductive tract is uncommon, with most cases involving the uterine corpus or ovary. Patients with non-leukaemic myeloid sarcoma are treated with acute myeloid leukaemia (AML) regimens, but the optimal therapy is unclear due to the relative rarity of the condition and lack of clinical trial data. We present an unusual case of myeloid sarcoma of the uterine cervix diagnosed incidentally in a patient with cervical-intraepithelial neoplasia grade 2 (CIN2), followed by a literature review.

The Progression of Chronic Myeloid Leukemia to Myeloid Sarcoma: A Systematic Review

Chronic myeloid leukemia (CML) is a slow-growing type of cancer that originates in the blood-forming cells of the bone marrow and is caused by a chromosomal mutation that is thought to occur spontaneously. CML could potentially lead to the development of myeloid sarcoma (MS), which is a rare neoplasm composed of immature myeloid cells that could evolve into a tumor mass at any anatomical site other than the bone marrow. MS can develop spontaneously or as a result of another form of myeloid neoplasm. Most instances of CML precede blast phase (BP) within two to three years after the first diagnosis of CML chronic phase (CP) at the age of pre-tyrosine kinase inhibitor (TKI) treatment. MS developing in CML patients during the era of TKI treatment is infrequently mentioned in the literature, primarily in single-case studies. As a result, the prognostic influence of MS in CML patients has not been well investigated. In the age of TKI treatment, it is uncertain whether MS and medullary BP have comparable clinical and prognostic relevance. The precise diagnosis of MS is critical for effective treatment, which is frequently delayed due to a high risk of misdiagnosis. This review focuses on the relationship between the development of MS from CML, and it culminates with recommendations for future hematology practice. A literature search was conducted in multiple databases, and the studies were appraised based on the inclusion and exclusion criteria. Finally, studies to date have shown that the existence of CML and its possible progression to MS in individuals map out the numerous implications this disease has in hematology practice. Though occurrences are uncommon in general, the prognosis for patients is bleak, necessitating the exploration and implementation of diagnostic and therapy advancements. Because there is limited evidence in the literature on its existence in the medullary chronic phase and outcomes in the era of TKI, it must be carefully investigated because it might be the first symptom of progressive illness prior to hematological progression.

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.

Endovascular biopsy of a sigmoid sinus lesion using a stent retriever and aspiration catheter

A teenager with a history of acute myeloid leukemia presented with headache, nausea and blurry vision over a 2 week period. The MRI of the brain was concerning for the presence of a myeloid sarcoma within the right sigmoid sinus. For evaluation of venous obstruction and the underlying lesion the patient underwent a cerebral angiogram and transvenous biopsy of the sigmoid sinus lesion using a stent retriever and aspiration catheter. The tissue extracted was consistent with myeloid sarcoma. This pathologic finding was consistent with the recurrence of leukemia and guided the targeted oncologic treatment.

Case report: Rare myeloid sarcoma development following renal transplantation with KRAS and DNMT3A gene mutations

Background

A high incidence of malignant tumors, such as post-transplant lymphoproliferative disorders (PTLD), Kaposi sarcoma, and renal cancer is common in solid organ and bone marrow transplant recipients. However, myeloid sarcoma (MS) after renal transplantation has rarely been reported and the diagnosis is challenging due to its low incidence.

Case presentation

Here, we report a rare case of a 49-year-old man who developed myeloid sarcoma (MS) in the transplanted kidney two years after renal transplantation. Next-generation sequencing (NGS) showed mutations of KRAS and DNMT3A genes in the MS, and no gene mutations in the bone marrow. He presented a normal karyotype of 46, XY. Following treatment with 6 cycles of systemic chemotherapy, the patient was in satisfactory condition with stable serum creatinine (sCr) levels at the 1-year follow-up. In addition, we performed a detailed review with emphasis on the clinical manifestations, and the diagnostic and therapeutic processes of another 7 patients who developed MS following renal transplantation.

Conclusions

Our report illustrates the clinical utility of comprehensive genomic profiling in benefiting the diagnosis of MS, the selection of therapeutic strategy and the determination of whether MS is donor-derived.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01141-z.

Myeloid sarcoma as a manifestation of acute myeloid leukemia

We report a case of a 43-year-old man who presented with dyspnea because of large bilateral pleural effusions and imaging findings of a large periaortic mass with compression of the esophagus and left atrium. Subsequent soft tissue biopsy was consistent with myeloid sarcoma, and bone marrow biopsy was consistent with acute myeloid leukemia. He was started on induction and subsequent consolidation chemotherapy with complete remission and shrinkage of the tumor.

Isolated recurrence of acute myeloid leukemia in the cerebellum: illustrative case

BACKGROUND

Myeloid sarcoma is a rare malignant hematopoietic neoplasm that arises at extramedullary sites. Although myeloid sarcoma may involve any organ, central nervous system (CNS) involvement is exceptionally rare. To date, few case reports and case series have described CNS myeloid sarcoma, the majority of which include peripheral disease.

OBSERVATIONS

The authors present an illustrative case of an adult male with acute myeloid leukemia (AML) in remission relapsing with an isolated, diffuse myeloid sarcoma of the cerebellum. Magnetic resonance imaging showed posterior fossa crowding and diffuse enhancement within the cerebellar white matter without an apparent mass lesion. The patient required ventriculostomy due to obstructive hydrocephalus and ultimately suboccipital craniectomy with duraplasty due to posterior fossa compression. An open cerebellar biopsy revealed myeloid sarcoma. Peripheral studies did not meet the criteria for recurrent AML. The patient subsequently received high-dose systemic chemotherapy and has responded well to treatment.

LESSONS

Myeloid sarcoma may be a neurosurgical lesion because it has the potential to cause mass effect with obstructive hydrocephalus requiring emergent cerebrospinal fluid diversion and possible decompression. The authors report a rare case of isolated recurrence of AML in the form of diffuse CNS myeloid sarcoma and describe the role of neurosurgery in its diagnosis and treatment.

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.

Esophageal post-Therapy Myeloid Sarcoma masquerading as Poorly Differentiated Adenocarcinoma: A Diagnostic Pitfall

A 73-year-old male with complaints of dysphagia, fatigue and weight loss for the past one year underwent an upper gastrointestinal endoscopy, depicting a partially obstructing mass in the lower third of esophagus. An endoscopic ultrasound showed a hypoechoic mass with suggested invasion into the muscularis propria with two enlarged level 8 paraesophageal lymph nodes. By sonographic criteria, the tumor was staged as T3N1. Multiple biopsies confirmed poorly differentiated adenocarcinoma (cytokeratin positive) with gland formation (<50% of tumor) and with focal signet ring cells and some extracellular mucin (Figure 1A).

Isolated myeloid sarcoma of lumbar spine without bone marrow involvement: a rare case report and treatment dilemma

Granulocytic sarcoma, chloroma, myeloblastoma, or here referred as myeloid sarcoma (MS), is a rare extramedullary tumor composed of immature myeloid cells called myeloblasts. MS is seen most commonly in patients with acute myeloid leukemia and less frequently in chronic myeloid leukemia, myelodysplastic syndrome. In rarer instances, MS has been shown to precede the development of myeloid tumors by acute myeloblastic leukemia (AML). In particular, isolated MS involving spine is extremely rare. We herein present a rare case of isolated spinal MS in non-leukemic patient. This is a previously relatively healthy 47-year-old man who presented with signs of lumbar spinal cord compression, initially reported as schwannoma on imaging, later diagnosed with spinal MS on pathology. Further workup did not reveal any evidence of bone marrow or other hematological involvement. The patient successfully treated by L4/L5 laminectomy and debulking with subsequent radiation resulting in substantial decrease in size of tumor with significant improvement in symptoms during follow up. This case not only describes a rare case of isolated MS of lumbar spine, but also highlights the potential treatment challenges of such a rare diagnosis. We review the available literature, discuss available treatment options, and highlight the need for further investigations along with increased clinician awareness.

Liver Granulocytic Sarcoma With Megakaryocytic Differentiation: A Rare Extra Medullary Involvement That Warrants Liver Biopsy for Prompt Diagnosis

Granulocytic sarcoma (GS) is an extramedullary manifestation of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) or myeloproliferative neoplasms. The diagnosis depends on morphology, immunohistochemistry and flow cytometry. An unusual location of this tumor may mask its primary source, therefore, a strategy involving immediate symptom control, and investigation is crucial in preventing clinical deterioration. We present a case of a 53-year-old man who initially presented with tumor lysis syndrome and transaminitis, with a subsequent CT Scan that revealed multiple liver lesions. This case describes a rare clinical entity of granulocytic sarcoma as multiple hypoattenuating liver lesions mimicking metastatic disease in its radiographic appearance. Since the imaging features of hepatic masses are nonspecific, and considering the aggressive nature of AML with concomitant tumor lysis syndrome, a confirmatory prompt biopsy should routinely be considered.

Myeloid Sarcoma Type of Acute Promyelocytic Leukemia With a Cryptic Insertion of RARA Into FIP1L1: The Clinical Utility of NGS and Bioinformatic Analyses

Background

Acute promyelocytic leukemia (APL) is characterized by the presence of coagulopathy at onset and translocation t (15; 17) (q22; 21), meanwhile, other translocation variants of APL have also been reported. The FIP1L1-RARA fusion gene has recently been reported as a novel RARA-associated fusion gene.

Objectives

We report a case of de novo myeloid sarcoma (MS) type of APL with FIP1L1-RARA found by next-generation sequencing (NGS) that was not detected by conventional analyze analysis for RARA translocations.

Methods

We performed typical morphological, magnetic resonance imaging (MRI), conventional tests for PML-RARA dual-fusion translocation probe, high-through sequencing and NGS. Meanwhile, bioinformatics analyses were done by using public repositories, including ONCOMINE, COSMIC, and GeneMANIA analysis.

Results

A 28-month-old girl with a complex karyotype that includes 46,XX,t(4;17)(q12;q22)[9]/46,idem,del(16)(q22)[3]/45,idem,-x,-4,-9,-15,del(16)(q22),+marl,+mar2,+mar3[7]/46,xx[3], c.38G>A (p.Gly13Asp) in the KRAS gene, and a cryptic insertion of RARA gene into the FIP1L1 gene was diagnosed with APL complicated by the de novo MS.

Conclusion

We report a FIP1L1-RARA fusion in a child with APL who presented with an extramedullary tumor in the skull without the classic karyotype using NGS, whom we treated with good results. NGS analysis should be considered for APL variant cases. Further experimental studies to the association between the mutation in KRAS gene and FIP1L1-RARA fusion on the clinical phenotype and progression of APL are needed to identify more effective therapeutic targets for APL.

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.

Clinicopathologic Features of Myelodysplastic Syndromes Involving Lymph Nodes

Lymph nodes (LNs) involved by a myelodysplastic syndrome (MDS) are rare and uncommonly biopsied. In this study, we report 6 MDS patients who underwent an LN biopsy that showed MDS, and we summarize the clinicopathologic features of this cohort. All patients presented with lymphadenopathy (generalized in 5), 5 patients had splenomegaly, and 3 patients had hepatomegaly. Histologically, the LN architecture was distorted without complete effacement. MDS cells, mostly of the myeloid lineage, produced interfollicular expansion. These myeloid cells exhibited a spectrum of maturation, and immature and atypical forms were common, including eosinophils. Scattered megakaryocytes and nucleated erythroid cells were often present. Concurrent bone marrow aspirate and biopsy specimens in these patients showed persistent/resistant MDS. Following the diagnosis of LN involvement, patients did not respond well to therapy and all died by the time of the last follow-up, with a median survival of 6.7 months (range, 4.5 to 21.6 mo). In summary, patients with MDS uncommonly develop clinically evident lymphadenopathy prompting biopsy as a result of infiltration by MDS. MDS in LNs can be subtle, showing incomplete and sometimes mild distortion of the architecture, and ancillary studies including immunohistochemical and flow cytometric immunophenotypic analysis are often needed to establish the diagnosis. These data also suggest that the emergence of lymphadenopathy attributable to MDS is associated with poor treatment response and prognosis in MDS patients and that aggressive therapy or alternative treatment regimens need to be explored in this context.

Definition, Epidemiology, Pathophysiology, and Essential Criteria for Diagnosis of Pediatric Chronic Myeloid Leukemia

Simple Summary

The low incidence (1:1,000,000) of chronic myeloid leukemia (CML) in the first two decades of life presents an obstacle to accumulation of pediatric experience and knowledge on this leukemia. Biological features of CML are shared but also differing between adult and pediatric patients. This review aims; (i) to define the disease based on an unified terminology, (ii) to list the diseases to be considered as a differential diagnosis in children, (iii) to outlines the morphological, histopathological and immuno-phenotypical findings of pediatric CML, (iv) to illustrate rare but classical complications resulting from high white cell and platelet counts at diagnosis, and (v) to recommend a uniform approach for the diagnostic procedures to be applied. Evidently, only a clear detailed picture of all relevant features can lay the basis for standardized treatment approaches.

Abstract

Depending on the analytical tool applied, the hallmarks of chronic myeloid leukemia (CML) are the Philadelphia Chromosome and the resulting mRNA fusion transcript BCR-ABL1. With an incidence of 1 per 1 million of children this malignancy is very rare in the first 20 years of life. This article aims to; (i) define the disease based on the WHO nomenclature, the appropriate ICD 11 code and to unify the terminology, (ii) delineate features of epidemiology, etiology, and pathophysiology that are shared, but also differing between adult and pediatric patients with CML, (iii) give a short summary on the diseases to be considered as a differential diagnosis of pediatric CML, (iv) to describe the morphological, histopathological and immunophenotypical findings of CML in pediatric patients, (v) illustrate rare but classical complications resulting from rheological problems observed at diagnosis, (vi) list essential and desirable diagnostic criteria, which hopefully in the future will help to unify the attempts when approaching this rare pediatric malignancy.

Case Report: Myeloid Sarcoma Development During Treatment for B Cell Lymphoblastic Lymphoma in a Boy with KRAS/NRAS Gene Mutations

Here, we report a rare case of a 12-year-old boy who was initially diagnosed with B cell lymphoblastic lymphoma (BLBL) and developed myeloid sarcoma (MS) eight months after chemotherapy. Next-generation sequencing (NGS) showed mutations of KRAS and NRAS genes in both the bone marrow and lymph node. He presented an abnormal karyotype of 46, XY, -9, der (16) t (9; 16) (q13; q12), +mar. He received chemotherapy according to the South China Children's Leukemia Group 2016 protocol. Complete remission was achieved by the 15th day post-treatment. Eight months later and immediately prior to the start of maintenance therapy, the patient developed fever, skin nodules in both upper arms, and enlargement of bilateral testes. Pathological analysis of skin and testicular biopsies suggested the diagnosis of myeloid sarcoma (MS). Again, NGS examination showed mutations of KRAS and NRAS genes. The patient underwent haploidentical hematopoietic stem cell transplantation but unfortunately did not survive. The interval of eight-month interval between the initial disease onset and MS brings into question whether MS developed as part of the initial onset of disease or as a secondary tumor in association with chemotherapy. Thus, understanding the pathogenesis of MS involving abnormalities of lymphoid progenitors may assist in the prediction of prognosis and development of novel target therapies.

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.

Newly diagnosed isolated myeloid sarcoma-paired NGS panel analysis of extramedullary tumor and bone marrow

Isolated myeloid sarcoma (MS) is a rare malignancy in which myeloid blast forms tumors at various locations while the bone marrow (BM) remains cytomorphologically free from disease. We analyzed isolated MS from four patients and their BMs at initial diagnosis and follow-up, using a custom next-generation sequencing (NGS) panel. We observed possible clonal evolution and a clonal hematopoiesis of indeterminate potential (CHIP)-like finding in the BM of one of three cases with detectable mutations. Clinical presentation of one patient suggested extramedullary confined homing of blasts to distal sites in the relapse situation still sparing the BM. In summary, our findings shall motivate future work regarding signals of extramedullary blast trafficking and clonal evolution in MS.

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.

Targeted therapy for medullary and extramedullary relapse of FLT3-ITD acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation

We report a case with extramedullary tumors affecting the supraclavicular region that presented as a relapse of acute myeloid leukemia (AML) with FLT3-ITD mutation after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Treatment with gilteritinib resulted in remarkable response with disappearance of both the medullary and extramedullary tumors. Subsequently, a 2nd allo-HSCT was performed in an attempt to cure his AML and complete molecular response has been sustained with gilteritinib resumption without worsening GVHD. Targeted therapy with gilteritinib for medullary and extramedullary relapse of FLT3-ITD AML could be effective and suitable as a bridging therapy for allo-HSCT.

Extramedullary Acute Myeloid Leukemia of the Renal Pelvis: Insights into a Visceral Niche

Acute myeloid leukemia (AML) is a stem cell malignancy that originates in the bone marrow and involves the peripheral blood. Extramedullary AML is rarer, but it is most commonly associated with the former French-American-British (FAB) subtypes M4 or M5 of AML. AML cells may also home to the central nervous system and other solid organs such as cortical bone and skin. Such target sites of metastasis depend on microenvironmental niche interactions, which have not been fully elucidated to date. Visceral organs usually do not represent a favorable niche for AML stem cell occupancy. Herein, we describe the case of an 80-year-old man with extramedullary AML involvement of the renal pelvis. Hypercalcemia and obstructive uropathy were presenting features. The visceral niche is a rare site of involvement of myeloid malignancy, and hypercalcemia may reflect a mechanism of extramedullary involvement. We propose a treatment paradigm for this uncommon subset of AML based on advanced age and complex karyotype.

SET-CAN Fusion Gene in Acute Leukemia and Myeloid Neoplasms: Report of Three Cases and a Literature Review

Objective

To investigate the characteristics of hematological malignancies in patients with the SET-CAN fusion gene and provide a literature review.

Methods

We retrospectively analyzed the clinical data of three cases of acute leukemia and myeloid neoplasms harboring the SET-CAN fusion gene who were treated at our hospital. Their clinical manifestations, pathological results and treatment strategies were investigated.

Results

The three cases were diagnosed with T-cell acute lymphoblastic leukemia (T-ALL), acute myeloid leukemia (AML) and myeloid sarcoma (MS), respectively. Karyotype analyses identified a normal result in all three patients. Subsequently, we confirmed del(9q34) utilizing FISH analysis. Mutation of the BRAF gene was detected in case 1, while mutations in PHF6 and BCOR were detected in case 2, which have not been officially reported in patients with SET-CAN fusions. Finally, relevant literature focusing on adult patients with hematological malignancies harboring the SET-CAN fusion gene were summarized.

Conclusion

Adult patients with the SET-CAN fusion gene were rare among cases of hematological malignancies. There was a large degree of heterogeneity between different patients. Notably, some patients remained sensitive to chemotherapy. Overall prognosis may be related to the type of disease and other cytogenetic abnormalities. Systemic cytogenetic and molecular studies are needed to make accurate diagnoses. Additional cases need to be accumulated and summarized to better understand these diseases.

Extra-medullary recurrence of myeloid leukemia as myeloid sarcoma after allogeneic stem cell transplantation: impact of conditioning intensity

Myeloid sarcoma (MS) as a solid extra-medullary (EM) manifestation of acute myeloid leukemia (AML), myeloproliferative or myelodysplastic syndromes is a rare presentation of relapse after allogeneic hematopoietic stem cell transplantation (HSCT). The databases of the Departments of Hematology and Oncology of the University Hospitals of Jena and Rostock were screened for patients aged 18 years or older for onset of MS after HSCT for myeloid malignancies between 2002 and 2019. Nineteen patients with MS were identified, the majority of whom had received reduced-intensity conditioning (RIC). The median onset of MS was 425 days after HSCT and the median overall survival since MS was 234 days. Although MS is associated with a poor prognosis, three patients survived more than two years and one more than 11 years after MS onset. These results indicate that RIC protocols may be associated with a higher risk of EM relapse. Since EM relapse occurred in the presence of Graft-versus-host-disease, these observations also demonstrate the limitations of graft-versus-tumor effects after HSCT. In conclusion, occurrence of MS after HSCT is associated with a poor prognosis, as multimodal curative concepts including intensive chemotherapy and another HSCT are often not viable.

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.

Pediatric myeloid sarcoma: a single institution clinicopathologic and molecular analysis

Myeloid sarcoma (MS) is a neoplastic condition composed of immature myeloid cells involving an extramedullary site. We investigated underlying chromosomal and molecular alterations to assess potential molecular markers of prognosis and outcome in this rare pediatric disease. We conducted a retrospective review of clinicopathologic and cytogenetic data from 33 pediatric patients with MS (ages 1 month-18 years) at our institution over a 32 year period (1984-2016). Tissue-based cancer microarray and targeted next-generation sequencing analysis were performed on six cases. The median age at diagnosis was 2.8 years with a male-to-female ratio of 2.6:1. MS is commonly presented with concomitant marrow involvement (n = 12, 36.4%) or as a recurrence of acute myeloid leukemia (AML; n = 14, 42.4%). The skin (n = 18, 54.5%) and soft tissue (n = 9, 27.3%) were the most common sites of involvement. Twenty-one of 25 samples (84.0%) harbored chromosomal aberrations; KMT2A alterations (n = 10, 40.0%) or complex cytogenetics (n = 7, 28.0%) were most frequent. Mutations in RAS, tyrosine kinase, cell signaling, and chromatin remodeling genes were detected. When compared to pediatric patients with AML without extramedullary involvement (EMI), inferior overall survival (OS) was observed (18.8 months vs. 89.3 months, p = .008). Pediatric patients with MS with non-favorable cytogenetics [abnormalities other than t(8;21), inv(16)/t(16;16), or t(15;17)] had a significantly lower OS compared to patients with AML with non-favorable cytogenetics and no extramedullary involvement (8.0 months vs. 28.1 months, p < .001). Pediatric MS is a rare disease with diverse clinical presentations. Non-favorable cytogenetics may be a poor prognostic marker for pediatric patients with MS and molecular diagnostics can assist with risk stratification and identify potentially actionable targets.

Myeloid sarcoma is associated with poor clinical outcome in pediatric patients with acute myeloid leukemia

PURPOSE

The impact of myeloid sarcoma (MS) on clinical outcome of pediatric acute myeloid leukemia (AML) patients remains controversial. Moreover, little is known about the role of stem cell transplantation (SCT) in such patients.

METHODS

Clinical data of patients with AML under 18 years of age were retrieved from the TARGET dataset. We analyzed the prevalence, clinical profile, molecular characteristics, and prognosis of MS in these patients.

RESULTS

Among 884 pediatric patients with AML, the frequency of MS was 12.3%. Pediatric AML with MS was associated with age under 1-year, abnormal cytogenetics, and KMT2A rearrangement. Moreover, MS was associated with a low complete remission rate, high induction death, poor 5-year EFS, and OS. KMT2A rearrangement had a negative impact on clinical outcome in AML patients with MS. In addition, SCT had no significant effect on the survival of AML patients with MS. Multivariate analysis revealed that MS was an unfavorable prognostic factor in pediatric AML in terms of EFS (Hazard ratio 1.670, P < 0.001) and OS (Hazard ratio 1.623, P = 0.004).

CONCLUSIONS

The presence of MS at diagnosis of pediatric AML is associated with poor clinical outcomes, particularly when associated with KMT2A rearrangements. Moreover, pediatric patients with AML and MS may not benefit from SCT.

Educational Case: Myeloid Sarcoma: A Subtype of Acute Myeloid Leukemia

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹