Integrin-α9 overexpression underlies the niche-independent maintenance of leukemia stem cells in acute myeloid leukemia.

Leukemia stem cells (LSCs) are widely believed to reside in well-characterized bone marrow (BM) niches; however, the capacity of the BM niches to accommodate LSCs is insufficient, and a significant proportion of LSCs are instead maintained in regions outside the BM. The molecular basis for this niche-independent behavior of LSCs remains elusive. Here, we show that integrin-α9 overexpression (ITGA9 OE) plays a pivotal role in the extramedullary maintenance of LSCs by molecularly mimicking the niche-interacting status, through the binding with its soluble ligand, osteopontin (OPN). Retroviral insertional mutagenesis conducted on leukemia-prone Runx-deficient mice identified Itga9 OE as a novel leukemogenic event. Itga9 OE activates Akt and p38MAPK signaling pathways. The elevated Myc expression subsequently enhances ribosomal biogenesis to overcome the cell integrity defect caused by the preexisting Runx alteration. The Itga9-Myc axis, originally discovered in mice, was further confirmed in multiple human acute myeloid leukemia (AML) subtypes, other than RUNX leukemias. In addition, ITGA9 was shown to be a functional LSC marker of the best prognostic value among 14 known LSC markers tested. Notably, the binding of ITGA9 with soluble OPN, a known negative regulator against HSC activation, induced LSC dormancy, while the disruption of ITGA9-soluble OPN interaction caused rapid cell propagation. These findings suggest that the ITGA9 OE increases both actively proliferating leukemia cells and dormant LSCs in a well-balanced manner, thereby maintaining LSCs. The ITGA9 OE would serve as a novel therapeutic target in AML.

TAFRO Syndrome and COVID-19.

TAFRO syndrome is a systemic inflammatory disease characterized by thrombocytopenia and anasarca. It results from hyperinflammation and produces severe cytokine storms. Severe acute respiratory syndrome coronavirus 2, which led to the coronavirus disease 2019 (COVID-19) pandemic, also causes cytokine storms. COVID-19 was reported to be associated with various immune-related manifestations, including multisystem inflammatory syndrome, hemophagocytic syndrome, vasculitis, and immune thrombocytopenia. Although the pathogenesis and complications of COVID-19 have not been fully elucidated, the pathogeneses of excessive immunoreaction after COVID-19 and TAFRO syndrome both involve cytokine storms. Since the COVID-19 pandemic, there have been a few case reports about the onset of TAFRO syndrome after COVID-19 or COVID-19 vaccination. Castleman disease also presents with excessive cytokine production. We reviewed the literature about the association between TAFRO syndrome or Castleman disease and COVID-19 or vaccination against it. While the similarities and differences between the pathogeneses of TAFRO syndrome and COVID-19 have not been investigated previously, the cytokines and genetic factors associated with TAFRO syndrome and COVID-19 were reviewed by examining case reports. Investigation of TAFRO-like manifestations after COVID-19 or vaccination against COVID-19 may contribute to understanding the pathogenesis of TAFRO syndrome.

Small sized centroblasts as poor prognostic factor in follicular lymphoma - Based on artificial intelligence analysis.

Histological assessment of centroblasts is an important evaluation in the diagnosis of follicular lymphoma, but there is substantial observer variation in assessment among hematopathologists. We aimed to perform quantitative morphological analysis of centroblasts in follicular lymphoma using new artificial intelligence technology in relation to the clinical prognosis. Hematoxylin and eosin slides of lesions were prepared from 36 cases of follicular lymphoma before initial chemotherapy. Cases were classified into three groups by clinical course after initial treatment. The 'excellent prognosis' group were without recurrence or progression of follicular lymphoma within 60 months, the 'poor prognosis' group were those that had relapse, exacerbation, or who died due to the follicular lymphoma within 60 months, and the 'indeterminate prognosis' group were those without recurrence or progression but before the passage of 60 months. We created whole slide images and image patches of hematoxylin and eosin sections for all cases. We designed an object detection model specialized for centroblasts by fine-tuning YOLOv5 and segmented all centroblasts in whole slide images. The morphological characteristics of centroblasts in relation to the clinical prognosis of follicular lymphoma were analyzed. Centroblasts in follicular lymphoma of the poor prognosis group were significantly smaller in nuclear size than those in follicular lymphoma of the excellent prognosis group in the following points: median of nuclear area (p = 0.013), long length (p = 0.042), short length (p = 0.007), nuclear area of top 10 % cells (p = 0.024) and short length of top 10 % cells (p = 0.020). Cases with a mean nuclear area of <55 µm2 had poorer event-free survival than those with a mean nuclear area of ≥55 µm2 (p < 0.0123). AI methodology is suggested to be able to surpass pathologist's observation in capturing morphological features. Small-sized centroblasts will likely become a new prognostic factor of follicular lymphoma.

Central nervous system relapse after combination therapy including polatuzumab vedotin in patients with diffuse large B-cell lymphoma.

Preventing central nervous system (CNS) relapse is a major challenge in the treatment of diffuse large B-cell lymphoma (DLBCL). However, no previous studies have examined the efficacy of polatuzumab vedotin (PV)-containing regimens in preventing CNS relapse in patients with DLBCL. Here, we report two cases of CNS relapse after PV-containing chemotherapy for DLBCL. CNS relapse developed during combination therapy with PV, bendamustine, and rituximab (PV-BR) in one patient and six months after PV-BR in the other patient. PV-containing chemotherapy may be ineffective as a prophylaxis against CNS relapse; therefore, additional strategies for preventing CNS relapse in DLBCL patients are required.

[Veno-venous extracorporeal membrane oxygenation for capillary leak syndrome during induction chemotherapy in acute myeloid leukemia].

A 44-year-old woman was diagnosed with acute myeloid leukemia (RUNX1::RUNX1T1 translocation) and received induction chemotherapy with idarubicin hydrochloride and cytosine arabinoside. The pneumonia that had been present since admission worsened, and a drug-induced skin rash appeared. On day 17, she presented with respiratory failure and shock, complicated by hemoconcentration and hypoalbuminemia. This was considered capillary leak syndrome due to pneumonia and drug allergy, so she was started on pulse steroid therapy and IVIG, and was intubated on the same day. On day 18, venovenous-extracorporeal membrane oxygenation (VV-ECMO) was started due to worsening blood gas parameters despite ventilatory management. Bronchoalveolar lavage fluid was serous, and both blood and sputum cultures yielded negative. The patient was weaned from VV-ECMO on day 26 as the pneumonia improved with recovery of hematopoiesis. She was disoriented, and a CT scan on day 28 revealed cerebral hemorrhage. Her strength recovered with rehabilitation. After induction chemotherapy, RUNX1::RUNX1T1 mRNA was not detected in bone marrow. The patient received consolidation chemotherapy, and has maintained complete remission. Severe respiratory failure during induction chemotherapy for acute leukemia can be fatal, but VV-ECMO may be lifesaving.

Aortitis after switching short-acting granulocyte colony-stimulating factors in a lymphoma patient with HLA-B52.

Aortitis is a rare adverse event of granulocyte colony-stimulating factor (G-CSF) treatment. Several previous studies have described recurrent aortitis caused by re-administration of the same G-CSF. However, no previous studies have examined the safety of switching between short-acting G-CSFs in patients who develop aortitis. We report the case of a 55-year-old man with refractory diffuse large B-cell lymphoma, who developed G-CSF-associated aortitis. The aortitis was triggered by filgrastim and recurred after treatment with lenograstim. The patient possessed human leukocyte antigen B52, which has been implicated in Takayasu arteritis. In addition, a drug-induced lymphocyte stimulation test for lenograstim performed upon detection of recurrent G-CSF-associated aortitis produced a positive result. Our case suggests that switching from one short-acting G-CSF to another does not prevent recurrence of G-CSF-associated aortitis. Although the etiology of G-CSF-associated aortitis has not been fully elucidated, our case also suggests that some patients may be genetically predisposed to aortitis.

Comparison of platelet transfusion effectiveness between Helicobacter pylori-positive and -negative immune thrombocytopenia.

Immune thrombocytopenia (ITP) is characterized by early platelet destruction and impaired platelet production. Helicobacter pylori (H. pylori) infection seems to contribute to the pathogenesis in certain ITP patients in Japan. We compared the effectiveness of platelet transfusion in severe ITP in the presence or absence of H. pylori. The median corrected count increment (CCI) at 24 h after platelet transfusion (CCI-24) of the H. pylori-positive ITP patients was higher than that of the H. pylori-negative ITP patients (6463 vs. 754, p < 0.001), and the CCI-1 was also in the same direction but not significant (23 351 vs. 11 578). Multiple regression analyses showed that H. pylori infection was independently associated with CCI-24. Our study suggests that platelet transfusion may be more effective in H. pylori-positive ITP patients.

IGLL5 controlled by super-enhancer affects cell survival and MYC expression in mature B-cell lymphoma.

IGLL5 is shown to be located near super-enhancer (SE) in B-cell tumors, and this gene is frequently mutated and a target of translocation in B-cell tumors. These results suggest roles of the IGLL5 in tumorigenesis; however, its functional properties have been unclear. We found that two mature B-cell lymphoma cell lines expressed IGLL5 mRNA with Cλ1 segment. JQ1 treatment resulted in down-expression of IGLL5, indicating that IGLL5 is controlled by SE. IGLL5 knockdown induced cell death with down-expression of MYC. Our results suggested that IGLL5 might have a role in survival of mature B-cell tumors and involvement in MYC expression. (100 words).

Comparison of two apheresis systems for granulocyte collection without hydroxyethyl starch.

BACKGROUND AND OBJECTIVES: Granulocyte transfusion (GTX) is a treatment option for severe infections in patients with neutropenia. In previous studies, hydroxyethyl starch (HES) was used to enhance red blood cell sedimentation for granulocyte collection (GC). However, there are safety concerns about HES, and HES is not readily available in some countries. Therefore, we compared the granulocyte counts and GC efficiency achieved by two apheresis systems without HES. MATERIALS AND METHODS: All consecutive GC procedures performed between July 2011 and March 2018 at our hospital were analysed. COBE Spectra was used until 5 February 2016, and Spectra Optia was used afterwards. HES was not used. RESULTS: Twenty-six GC procedures were performed, including 18 performed using COBE Spectra and 8 using Spectra Optia. When Spectra Optia was used, >1 × 1010 neutrophils were collected from seven of the eight (88%) procedures. Although there was no significant difference in the granulocyte yield between COBE Spectra-based and Spectra Optia-based GC procedures, the collection efficiency of Spectra Optia was significantly higher than that of COBE Spectra (p = 0.021). Furthermore, the granulocyte yields of Spectra Optia-based GC tended to be more strongly correlated with the peripheral blood neutrophil count on the day of apheresis than those of COBE Spectra-based GC. CONCLUSION: Our results suggest that Spectra Optia achieves greater GC efficiency than COBE Spectra, even without HES. GTX may be a therapeutic option for severe neutropenia, even in places where HES is not available.

Clinicopathological analysis of CD47 and signal regulatory protein alpha expression in myeloid sarcoma patients: CD47 expression is a favourable prognostic factor.

Myeloid sarcoma is a rare extramedullary haematopoietic malignancy. Interaction between CD47 and signal regulatory protein α (SIRPα) inhibits phagocytosis. CD47-positive tumours confer poor prognoses in various malignant tumours, including acute myeloid leukaemia. This study aimed to investigate the clinicopathological effects of CD47 and SIRPα expression in myeloid sarcoma. Immunohistochemistry (IHC) of CD47 and SIRPα was performed in 84 biopsy samples obtained from patients with myeloid sarcoma, some of which were CD47-positive. Patients were categorised into the following two groups based on IHC of SIRPα: those with SIRPα-positive neoplastic cells (nSIRPα) and, SIRPα expression on non-neoplastic stromal cells in tumour microenvironment (miSIRPα). In addition, patients with CD47 positivity had higher lymphocytic infiltration into the tumour microenvironment. Overall, these patients had significantly higher overall survival, however, no significant difference was observed in progression-free survival. No significant prognostic differences were observed between the nSIRPα and miSIRPα groups. This is the first study to demonstrate an association between CD47 expression and improved prognosis in myeloid sarcoma. Nonetheless, it will be necessary to conduct additional research on gene expression and genomic abnormalities to elucidate the corresponding pathogenesis of myeloid sarcoma.

Angioimmunoblastic T-Cell Lymphoma after Treatment of Classic Hodgkin Lymphoma: A Case Report.

We report a case of a 24-year-old man who developed angioimmunoblastic T-cell lymphoma (AITL) after treatment for refractory lymphocyte-rich classic Hodgkin lymphoma (LR-CHL). This patient was treated with the BV+AVD (brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine) protocol for LR-CHL but progressed before completing chemotherapy. The pathological imaging showed the typical findings of LR-CHL at the first onset and first progression. Rescue chemotherapy and high-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (AHSCT) were performed for refractory LR-CHL, and complete remission was achieved. However, the recurrence was suspected 6 months after AHSCT. The pathological findings of the lymph node biopsy at this time were different from those of the previous two lymph node biopsies, demonstrating findings of AITL. The finding of the immunohistochemical staining and polymerase chain reaction results supported the diagnosis. Although it has been reported that the risk for the development of non-Hodgkin lymphoma after treatment for Hodgkin lymphoma is increased, most are B-cell lymphomas, and few cases of AITL have been reported. AITL is a type of peripheral T-cell lymphoma that generally occurs in middle-aged and elderly people and that rarely occurs in young people. Here, we were able to make an accurate diagnosis by performing re-examination even when recurrence of LR-CHL was suspected. As there are no detailed case reports of AITL developing into secondary non-Hodgkin lymphoma, here we report on an identified case.

[Guillain-Barré syndrome associated with Epstein-Barr virus and cytomegalovirus reactivation during treatment for chronic graft-versus-host disease after allogeneic bone marrow transplantation].

Guillain-Barré syndrome (GBS) is a rare neurological complication of allogeneic hematopoietic stem cell transplantation (HSCT). The pathogenesis of post-HSCT GBS is unclear. Here, we report a case of GBS coincident with Epstein-Barr virus (EBV) and cytomegalovirus (CMV) reactivation that occurred after HSCT in a patient with myelodysplastic syndrome. A 61-year-old man was admitted to our hospital because of gait disturbance due to lower limb muscle weakness, which arose during treatment for chronic graft-versus-host disease (GVHD) five months after allogeneic HSCT. He was diagnosed with GBS based on his clinical course, cerebrospinal fluid analysis, and a nerve conduction study. At that time, he exhibited EBV and CMV reactivation. GBS improved after intravenous injection of immunoglobulins. Our case suggests that reactivation of EBV and CMV during treatment for chronic GVHD may induce GBS, and that rapidly progressive muscular weakness coincident with EBV or CMV reactivation can be a diagnostic sign of GBS after allogeneic HSCT.

Detection of the JAK2 V617F Mutation in Urinary Cell-free DNA in Patients with Myeloproliferative Neoplasms.

Objective Testing for the Janus activating kinase 2 (JAK2) V617F mutation is important for diagnosing and treating myeloproliferative neoplasms (MPNs). Recently, urine cell-free DNA (ucfDNA) was reported to be useful for detecting tumor-specific gene mutations in several solid tumors. However, its utility in detecting such mutations in hematological malignancies has not yet been assessed. In this study, we assessed whether or not the JAK2 V617F mutation could be detected in ucfDNA and whether or not its positivity rate in ucfDNA was associated with the JAK2 V617F allele ratio of peripheral blood cells in patients with MPN. Methods The JAK2 V617F allele ratio of genomic DNA from peripheral blood cells was determined using quantitative polymerase chain reaction (qPCR) or droplet digital PCR (ddPCR). ucfDNA was subjected to ddPCR. The correlation between the JAK2 V617F mutation positivity rates of blood-derived DNA and those of ucfDNA was assessed. Materials Twelve patients with polycythemia vera and 12 patients with essential thrombocythemia were enrolled. Ethylenediaminetetraacetic acid-treated peripheral blood (100 mL) and 15-30 mL of fresh urine were used. Results The JAK2 V617F mutation was detected in the ucfDNA from all 20 JAK2 V617F mutation-positive patients. In addition, the JAK2 V617F mutation positivity rate of ucfDNA was correlated with the JAK2 V617Fｓ allele ratio of blood-derived DNA, including in both estimated glomerular filtration rate (eGFR) groups (patients with an eGFR ≥50 or <50 mL/min/1.73 m2). Conclusion Our results indicate that ucfDNA is a valuable tool for diagnosing and monitoring MPN. Given these findings, other disease-specific gene mutations in hematological malignancies may also be detectable in ucfDNA.

Comparison of the outcomes of patients with primary central nervous system lymphoma between the neurosurgery and hematology/oncology departments based on the relative dose intensity of methotrexate.

Primary central nervous system lymphoma (PCNSL) is an extranodal type of lymphoma, which is treated with methotrexate (MTX)-based induction therapy. Although PCNSL is a hematological malignancy, patients with PCNSL may be treated at neurosurgery or hematology/oncology departments; however, the outcomes of PCNSL treatment have not been compared between these two departments. The present study compared the outcomes of 26 patients with newly diagnosed PCNSL that were treated at the Department of Neurological Surgery or Department of Hematology/Oncology (Wakayama Medical University Hospital, Wakayama, Japan) between January 2011 and December 2021. The relative dose intensity (RDI) and relative treatment intensity of MTX were assessed as indicators of the intensity of chemotherapy. The median RDI of MTX was 67 and 93% in the neurosurgery and hematology/oncology groups, respectively (P<0.001). The proportion of patients that achieved a complete response after high-dose MTX-based therapy was significantly higher in the hematology/oncology group than in the neurosurgery group (P=0.038). The estimated 2-year overall survival was 72 and 100% in the neurosurgery and hematology/oncology groups, respectively (P=0.046). As with the difference in the outcomes observed between pediatrics and hematology departments for adolescents with acute lymphoblastic leukemia, the outcomes of patients with PCNSL may differ between neurosurgery and hematology/oncology departments.

Administration of combined venetoclax and azacitidine in a patient with acute myeloid leukemia and multiple comorbidities undergoing dialysis: A case report.

Patients with acute myeloid leukemia (AML) who have comorbidities have limited treatment options, thereby resulting in poor prognosis. Venetoclax, a specific B-cell lymphoma-2 inhibitor, has recently been approved for AML in combination with hypomethylating agents; however, only one report has described its use in patients undergoing dialysis. Herein, we report the effectiveness of combined venetoclax and azacitidine in a 73-year-old man with AML undergoing dialysis and who was ineligible for standard therapies. The safety of venetoclax and azacitidine in patients undergoing dialysis has been reported, and their combination may be a feasible option for patients with AML undergoing dialysis.

Severe systemic inflammation mimicking TAFRO syndrome following COVID-19.

TAFRO syndrome is a rare systemic inflammatory disease. Its pathogenesis mainly involves excessive cytokine secretion and autoimmune dysfunction. Although its etiology is unclear, some viral infections have been reported to cause it. Here, we report a case of severe systemic inflammation mimicking TAFRO syndrome that arose after COVID-19. A 61-years-old woman suffered from a continuous fever, ascites, and edema after contracting COVID-19. She developed progressive thrombocytopenia, renal failure, and elevated C-reactive protein levels. She was tentatively diagnosed with multisystem inflammatory syndrome in adults (MIS-A) and received steroid pulse therapy. However, she exhibited worsening fluid retention and progressive renal failure, which are not typical of MIS-A. A bone marrow examination showed reticulin myelofibrosis and an increased number of megakaryocytes. Although a definitive diagnosis of TAFRO syndrome was not made according to current diagnostic criteria, we determined that her symptoms were clinically consistent with those of TAFRO syndrome. Combination therapy, including steroid pulse therapy, plasma exchange, rituximab, and cyclosporine, improved her symptoms. There are pathological similarities between hyperinflammation that arises after COVID-19 and TAFRO syndrome in terms of the associated cytokine storms. COVID-19 may have triggered the development of systemic inflammation mimicking TAFRO syndrome in this case.

Highly efficient Runx1 enhancer eR1-mediated genetic engineering for fetal, child and adult hematopoietic stem cells.

A cis-regulatory genetic element which targets gene expression to stem cells, termed stem cell enhancer, serves as a molecular handle for stem cell-specific genetic engineering. Here we show the generation and characterization of a tamoxifen-inducible CreERT2 transgenic (Tg) mouse employing previously identified hematopoietic stem cell (HSC) enhancer for Runx1, eR1 (+24 m). Kinetic analysis of labeled cells after tamoxifen injection and transplantation assays revealed that eR1-driven CreERT2 activity marks dormant adult HSCs which slowly but steadily contribute to unperturbed hematopoiesis. Fetal and child HSCs that are uniformly or intermediately active were also efficiently targeted. Notably, a gene ablation at distinct developmental stages, enabled by this system, resulted in different phenotypes. Similarly, an oncogenic Kras induction at distinct ages caused different spectrums of malignant diseases. These results demonstrate that the eR1-CreERT2 Tg mouse serves as a powerful resource for the analyses of both normal and malignant HSCs at all developmental stages.

Rituximab Monotherapy for Grade 2-3 Lymphomatoid Granulomatosis with Central Nervous System Involvement in a Patient Receiving Methotrexate for Rheumatoid Arthritis.

Lymphomatoid granulomatosis (LYG) is a rare lymphoproliferative disorder (LPD). The optimal management strategy of methotrexate (MTX) related-LPD with central nervous system (CNS) involvement and histological features of LYG remains unclear. We herein report a case of grade 2-3 LYG in a rheumatoid arthritis patient, in which an intracranial mass accompanied by hemorrhaging and pulmonary and skin lesions developed. The patient received successful rituximab monotherapy. The tumor cells in the skin and brain showed monoclonal and oligoclonal proliferation, respectively. Our case suggests that rituximab monotherapy may be effective against MTX-LPD with CNS involvement, especially in cases with LYG histology.

An evaluation based on relative treatment intensity in older patients treated with reduced-dose R-THP-COP therapy for diffuse large B-cell lymphoma: A multicenter retrospective cohort study.

INTRODUCTION: The number of older patients with diffuse large B-cell lymphoma (DLBCL) is increasing. Although the standard treatment for newly diagnosed younger patients with DLBCL has been established, no consensus has been reached regarding the optimal chemotherapy intensity and regimen for older patients with DLBCL. In addition, no method for evaluating treatment intensity in retrospective studies when different numbers of chemotherapy courses are administered has been elucidated. MATERIALS AND METHODS: A multicenter retrospective analysis was conducted to evaluate the outcomes of a reduced-dose R-THP-COP regimen, which included 30 mg/m2 of pirarubicin, in 54 patients with DLBCL who were aged ≥75. To assess treatment intensity, we defined the relative treatment intensity (RTI) as the number of courses administered multiplied by the relative dose intensity (RDI). RESULTS: The estimated four-year overall survival rates (OS) of the patients aged 75-80 and ≥ 80 were 55.1% and 60.6%, respectively. There was no significant difference in four-year OS between these age groups. In our cohort, there was no significant difference in the estimated four-year OS between the patients who received reduced-dose R-THP-COP at an RDI of ≥61% and those that received it at an RDI of <61% (P = 0.35). On the other hand, the patients who received reduced-dose R-THP-COP at an RTI of ≥2.7 exhibited a significantly higher estimated four-year OS than those treated at an RTI of <2.7 (68.5% vs. 28.7%; P < 0.001). Multivariate analysis revealed that the RTI was a significant independent predictor of OS. The cumulative incidence of treatment-related mortality (TRM) at one year was 4.2% and 3.4% in the 75-80 and ≥ 80 age groups, respectively. The cumulative incidence of TRM was significantly worse among the patients with Charlson Comorbidity Index (CCI) scores of ≥2 than among those with CCI scores of 0 or 1. DISCUSSION: Our study suggests that the reduced-dose R-THP-COP regimen is a suitable treatment option for older patients with DLBCL, especially those with CCI scores of <2. Our study also showed that the RTI may be a valuable tool for assessing treatment intensity in retrospective studies involving older patients.

Intestinal Mucosa-Associated Lymphoid Tissue Lymphoma Transforming into Diffuse Large B-Cell Lymphoma in a Young Adult Patient with Neurofibromatosis Type 1: A Case Report.

Background: Neurofibromatosis type 1 (NF1) is a hereditary cancer syndrome characterized by multiple café-au-lait macules on the skin. Lymphoproliferative malignancies associated with NF1 are limited, although the most common are brain tumors. Case presentation: A 22-year-old woman with NF1 was admitted due to abdominal pain and bloody diarrhea. Her laboratory data exhibited macrocytic anemia and elevated IgA levels. Image studies showed diffuse increased wall thickening in the transverse and descending colon without lymphadenopathy and hepatosplenomegaly. A colonoscopy revealed a hemorrhagic ulcerated mass. Pathological analysis of the tumor tissues confirmed IgA-expressing mucosa-associated lymphoid tissue (MALT) lymphoma with histological transformation. Moreover, whole-exome sequencing in tumor tissues and peripheral blood mononuclear cells identified a somatic frameshift mutation of the A20 gene, which represents the loss of function. The patient responded well to R-CHOP chemotherapy, but the disease relapsed after 1 year, resulting in a lethal outcome. Conclusions: MALT lymphoma in children and young adults is extremely rare and is possibly caused by acquired genetic changes. This case suggests a novel association between hereditary cancer syndrome and early-onset MALT lymphoma.