Splenectomy unveils thrombocytosis in underlying myeloproliferative neoplasms with extrahepatic portal vein obstruction.

Extrahepatic portal vein obstruction (EHPVO) is a rare disease with myeloproliferative neoplasm (MPN) as the most common cause. We report that hypersplenic hematologic changes in EHPVO might be eliminated by MPN. Through experience with splenectomy for variceal control with EHPVO, we suspected that spleen might mask MPN-induced thrombocytosis, and that MPN might have a significant influence on excessive thrombocytosis after splenectomy. To clarify the influence of MPN and spleen on platelet trends, we conducted a retrospective hospital database analysis, evaluating 8 EHPVO patients with splenectomy (2 males, 6 females; from 17 years to 64 years, mean 38.3 years). Three (37.5%) of 8 were diagnosed as MPN by JAK2V617F mutation. The perioperative serum platelet counts in EHPVO without MPN were 10.5, 35.4, and 36.6 (x104/µL) preoperatively, after 1 week and 3 weeks, respectively. The platelet counts in EHPVO with MPN were 34.2, 86.4, and 137.0 (x104/µL), respectively. Splenectomy and MPN showed positive interaction on platelet increasing with statistical significance. We also examined the spleen volume index (SpVI: splenic volume (cm3) / body surface area (m2) and postoperative platelet elevations ratio (PER: 3-week postoperative platelet counts / preoperative platelet counts). However, both SpVI and PER showed no significant difference with or without MPN. Histological examination revealed splenic congestion in all 8 EHPVO cases, and splenic extramedullary hematopoiesis in 2 of 3 MPN. In EHPVO with MPN, hypersplenism causes feigned normalization of platelet count by masking MPN-induced thrombocytosis; however, splenectomy unveils postoperative thrombocytosis. Spleen in EHPVO with MPN also participates in extramedullary hematopoiesis.

An Unusual Case of Extramedullary Hematopoiesis in the Right Kidney.

Extramedullary hematopoiesis (EMH) is the formation of blood cells outside the bone marrow, typically occurring in response to chronic anemia or bone marrow dysfunction. While EMH is most commonly observed in the liver, spleen, and lymph nodes, its occurrence in the kidney is exceedingly rare. In this case report, we are presenting a case of a 49-year-old male diagnosed with polycythemia vera who had an incidental right renal mass, which was histo-pathologically proven as extramedullary hematopoiesis in the right kidney mimicking lymphoma. This case underscores the importance of considering EMH in the differential diagnosis of renal masses, especially in patients with a history of myeloproliferative disorders. Early recognition and appropriate management are crucial to avoid unnecessary interventions and manage the underlying hematological condition effectively. Accurate diagnosis through histopathological examination is crucial to avoid unnecessary surgical interventions.

Idiopathic multicentric Castleman disease with marrow fibrosis and extramedullary hematopoiesis.

BACKGROUND: Idiopathic multicentric Castleman disease (iMCD) is a rare inflammatory disorder mediated by excessive proinflammatory cytokine signaling, most notably by interleukin 6 (IL-6). IL-6-induced extramedullary hematopoiesis (EMH) has been reported in murine models of iMCD. Herein we present four cases of iMCD with EMH in humans. CASE SERIES: The index case is a 24-year-old white woman who presented with pancytopenia, hepatosplenomegaly, and diffuse lymphadenopathy (LAD) with EMH in core lymph node biopsies. We then searched ACCELERATE, a Castleman disease (CD) natural history registry, and identified three additional CD cases with EMH reported in biopsies: A 23-year-old Asian man with fatigue, edema, LAD, and splenomegaly; a 20-year-old white man with fever, dyspnea, LAD, and hepatosplenomegaly; and a 50-year-old white man with constitutional symptoms, LAD, and myelodysplastic syndrome in bone marrow with a KRAS mutation. RESULTS: All four patients presented with thrombocytopenia and fever and/or markedly elevated C-reactive protein. Patient 1 had iMCD-NOS (not otherwise specified) with severe thrombocytopenia, reticulin fibrosis in bone marrow, small volume LAD and organomegaly but no anasarca. The other three patients had iMCD-TAFRO (thrombocytopenia, anasarca, reticulin fibrosis, renal dysfunction, organomegaly). Two had mixed CD and two had hypervascular CD in lymph nodes. All four had bone marrow hypercellularity and megakaryocyte hyperplasia and two had reticulin fibrosis. CONCLUSIONS: This case series demonstrates that EMH can be seen in CD, particularly in iMCD-TAFRO. Given the similarity of this finding to previous murine models of IL-6-induced marrow and lymph node changes we hypothesize that this is an IL-6-mediated phenomenon.

Targeting erythroid progenitor cells for cancer immunotherapy.

Immunotherapy, especially immune checkpoint blockade therapy, represents a major milestone in the history of cancer therapy. However, the current response rate to immunotherapy among cancer patients must be improved; thus, new strategies for sensitizing patients to immunotherapy are urgently needed. Erythroid progenitor cells (EPCs), a population of immature erythroid cells, exert potent immunosuppressive functions. As a newly recognized immunosuppressive population, EPCs have not yet been effectively targeted. In this review, we summarize the immunoregulatory mechanisms of EPCs, especially for CD45+ EPCs. Moreover, in view of the regulatory effects of EPCs on the tumor microenvironment, we propose the concept of EPC-immunity, present existing strategies for targeting EPCs, and discuss the challenges encountered in both basic research and clinical applications. In particular, the impact of existing cancer treatments on EPCs is discussed, laying the foundation for combination therapies. The aim of this review is to provide new avenues for improving the efficacy of cancer immunotherapy by targeting EPCs.

Angelica sinensis polysaccharides promote extramedullary stress erythropoiesis via ameliorating splenic glycolysis and EPO/STAT5 signaling-regulated macrophages.

Conventional treatments exhibit various side effects on chronic stress anemia. Extramedullary stress erythropoiesis is a compensatory mechanism, which may effectively counteract anemia. Angelica sinensis polysaccharides (ASP) are the main active ingredient found in Angelica sinensis and exhibit antioxidant and hematopoietic effects. However, the effects of ASP on extramedullary stress erythropoiesis remain to be unclear. Here, we demonstrated the protective effects of ASP on chemotherapeutic drug 5-fluorouracil (5-FU)-induced decline in peripheral blood parameters such as RBC counts, HGB, HCT, and MCH, and the decline of BFU-E colony enumeration in the bone marrow. Meanwhile, ASP promoted extramedullary erythropoiesis, increasing cellular proliferation in the splenic red pulp and cyclin D1 protein expression, abrogating phase G0/G1 arrest of c-kit+ cells in mouse spleen. RT-qPCR and immunohistochemistry further revealed that ASP increased macrophage chemokine Ccl2 genetic expression and the number of F4/80+ macrophages in the spleen. The colony-forming assay showed that ASP significantly increased splenic BFU-E. Furthermore, we found that ASP facilitated glycolytic genes including Hk2, Pgk1, Pkm, Pdk1, and Ldha via PI3K/Akt/HIF2α signaling in the spleen. Subsequently, ASP declined pro-proinflammatory factor IL-1ß, whereas upregulating erythroid proliferation-associated genes Gdf15, Bmp4, Wnt2b, and Wnt8a. Moreover, ASP facilitated EPO/STAT5 signaling in splenic macrophages, thus enhancing erythroid lineage Gata2 genetic expression. Our study indicated that ASP may improve glycolysis, promoting the activity of splenic macrophages, subsequently promoting erythroid progenitor cell expansion. Additionally, ASP facilitates erythroid differentiation via macrophage-mediated EpoR/STAT5 signaling; suggesting it might be a promising strategy for stress anemia treatment.

Spinal extramedullary hematopoiesis mimicking an epidural tumor in a patient with high-risk polycythemia vera: illustrative case.

BACKGROUND: Here the authors present the case of a 43-year-old male with a history of T-cell lymphoma, which was treated with azacitidine plus cyclophosphamide, doxorubicin, vincristine, and prednisone and autologous hematopoietic cell transplant, and high-risk polycythemia vera (PCV) presenting with severe lower-back pain radiating to the bilateral legs with associated lower-extremity weakness and splenomegaly. OBSERVATIONS: T2-weighted magnetic resonance imaging revealed multilevel epidural lesions involving T1-10 and S1-2. Because of severe spinal canal stenosis, the patient underwent surgical decompression of T5-7, with immediate postoperative alleviation of the lower-extremity pain and complete resolution of the lower-leg weakness. Biopsy results revealed extramedullary hematopoiesis (EMH) mimicking a spinal epidural tumor. EMH is radiosensitive and displays a rapid response to low dosages, so the patient was further treated with palliative radiation therapy for residual tumors and symptom alleviation, as well as hydroxyurea and corticosteroids as indicated for cytoreduction. LESSONS: EMH associated with PCV or myeloproliferative conditions occurring within the spine is a rare phenomenon without a standard treatment approach. https://thejns.org/doi/10.3171/CASE23659.

Interplay of the heart, spleen, and bone marrow in heart failure: the role of splenic extramedullary hematopoiesis.

Improvements in therapies for heart failure with preserved ejection fraction (HFpEF) are crucial for improving patient outcomes and quality of life. Although HFpEF is the predominant heart failure type among older individuals, its prognosis is often poor owing to the lack of effective therapies. The roles of the spleen and bone marrow are often overlooked in the context of HFpEF. Recent studies suggest that the spleen and bone marrow could play key roles in HFpEF, especially in relation to inflammation and immune responses. The bone marrow can increase production of certain immune cells that can migrate to the heart and contribute to disease. The spleen can contribute to immune responses that either protect or exacerbate heart failure. Extramedullary hematopoiesis in the spleen could play a crucial role in HFpEF. Increased metabolic activity in the spleen, immune cell production and mobilization to the heart, and concomitant cytokine production may occur in heart failure. This leads to systemic chronic inflammation, along with an imbalance of immune cells (macrophages) in the heart, resulting in chronic inflammation and progressive fibrosis, potentially leading to decreased cardiac function. The bone marrow and spleen are involved in altered iron metabolism and anemia, which also contribute to HFpEF. This review presents the concept of an interplay between the heart, spleen, and bone marrow in the setting of HFpEF, with a particular focus on extramedullary hematopoiesis in the spleen. The aim of this review is to discern whether the spleen can serve as a new therapeutic target for HFpEF.

Tumor-like conditions that mimic liver tumors.

Non-neoplastic tumor-like conditions of the liver can appear similar to hepatic neoplasms. In many cases, a biopsy is required to confirm the pathology. However, several tumor-like conditions can be correctly diagnosed or suggested prospectively, thus saving patients from unnecessary anxiety and expense. In this image-focused review, we present the ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography scan features of eight such entities. Clues that indicate the correct pathology are discussed, and the usual clinical setting is described. Many of these lesions are treated differently from true neoplasms, and the current treatment plan is discussed in many of the cases presented. After reviewing this article, the reader will have a better understanding of these lesions and the situations in which they should be included in the differential diagnosis.

Noninfectious Ascites Neutrophilia in a Patient With Polycythemia Vera.

A 59-year-old woman with polycythemia vera-related portal hypertension requiring frequent paracentesis was admitted for asymptomatic recurrent spontaneous bacterial peritonitis, which was diagnosed based on elevated polymorphonuclear (PMN) count. She had multiple similar admissions during which she was treated with antibiotics. The patient had chronic baseline leukocytosis due to polycythemia vera. Repeat paracentesis after intravenous antibiotics demonstrated persistent elevation of PMN count without clinical symptoms. A multidisciplinary team concluded that the increased PMN count was secondary to polycythemia. The patient was diagnosed with omental extramedullary hematopoiesis, a rare condition causing elevated PMN count in the absence of bacterial contamination.

Unusual painful pelvic masses: Extramedullary hematopoiesis with extramedullary multiple myeloma.

The coexistence of extramedullary hematopoiesis and extramedullary multiple myeloma can occur and present as painful pelvic masses. In such a case, normal hematopoietic cells may outnumber clonal plasma cells, posing a diagnostic challenge.

Luspatercept's use in a patient with transfusion-dependent beta-thalassemia and intrathoracic extramedullary hematopoiesis (EMH).

Key Clinical Message: This case report and literature review examine the use of a relatively novel agent in a transfusion-dependent beta-thalassemia patient with extramedullary hematopoiesis (EMH). It examines the benefits and risks associated with its use and reviews the available literature while highlighting the drug's results in our patient with a higher risk profile. Abstract: Beta thalassemia can be complicated by EMH, which causes different symptoms based on location and size. Luspatercept is a new agent approved for transfusion-dependent thalassemia and Non-transfusion-dependent thalassemia (NTDT). Still, its use in patients with EMH was not well studied, and literature showed an increased risk of EMH expansion or development of new masses after its use. We discuss, in this case, the results of luspatercept treatment in a patient with transfusion-dependent thalassemia who is considered high risk for its use due to the patient's specific characteristics (history of symptomatic intrathoracic EMH, previous splenectomy, refusal to use antithrombotic medications). While also highlighting the benefits of using luspatercept regarding decreasing the iron overload and improving hemoglobin levels and examining how it was used safely to manage a transfusion-dependent thalassemia patient with an extramedullary hematopoiesis mass with no adverse events of note.

Survivors of polymicrobial sepsis are refractory to G-CSF-induced emergency myelopoiesis and hematopoietic stem and progenitor cell mobilization.

Sepsis survivors exhibit immune dysfunction, hematological changes, and increased risk of infection. The long-term impacts of sepsis on hematopoiesis were analyzed using a surgical model of murine sepsis, resulting in 50% survival. During acute disease, phenotypic hematopoietic stem and progenitor cells (HSPCs) were reduced in the bone marrow (BM), concomitant with increased myeloid colony-forming units and extramedullary hematopoiesis. Upon recovery, BM HSPCs were increased and exhibited normal function in the context of transplantation. To evaluate hematopoietic responses in sepsis survivors, we treated recovered sham and cecal ligation and puncture mice with a mobilizing regimen of granulocyte colony-stimulating factor (G-CSF) at day 20 post-surgery. Sepsis survivors failed to undergo emergency myelopoiesis and HSPC mobilization in response to G-CSF administration. G-CSF is produced in response to acute infection and injury to expedite the production of innate immune cells; therefore, our findings contribute to a new understanding of how sepsis predisposes to subsequent infection.

Unraveling a Rare Case of Epidural Extramedullary Hematopoiesis in a Patient With Transfusion-Dependent Beta Thalassemia Presenting With Spinal Cord Compression.

Thalassemia is known to induce extramedullary hematopoiesis (EMH), which is a compensatory mechanism in which the body forms blood cells outside the bone marrow. While EMH typically affects organs such as the spleen and liver, there are rare instances where it leads to spinal cord compression (SCC) in the epidural space. A 31-year-old male patient with transfusion-dependent beta thalassemia presented with numbness and bilateral limb weakness due to EMH. Neurological examination revealed increased tone in both legs, reduced power, loss of crude touch and pain sensation, and increased deep tendon reflexes. Magnetic resonance imaging (MRI) indicated a lobulated soft tissue structure in the posterior dural intrathecal space causing SCC. Laminectomy of the T2-T8 vertebrae was done, after which the lesion was identified and completely removed. Post-surgery, significant neurological improvements were observed in both motor and sensory functions. Thalassemia patients presenting with symptoms of SCC should be investigated for the presence of epidural EMH. Treatment options include decompressive surgery, blood transfusions, hydroxyurea, and radiotherapy.

Wnt5 controls splenic myelopoiesis and neutrophil functional ambivalency during DSS-induced colitis.

Neutrophils are important innate immune cells with plasticity, heterogenicity, and functional ambivalency. While bone marrow is often regarded as the primary source of neutrophil production, the roles of extramedullary production in regulating neutrophil plasticity and heterogenicity in autoimmune diseases remain poorly understood. Here, we report that the lack of wingless-type MMTV integration site family member 5 (WNT5) unleashes anti-inflammatory protection against colitis in mice, accompanied by reduced colonic CD8+ T cell activation and enhanced splenic extramedullary myelopoiesis. In addition, colitis upregulates WNT5 expression in splenic stromal cells. The ablation of WNT5 leads to increased splenic production of hematopoietic niche factors, as well as elevated numbers of splenic neutrophils with heightened CD8+ T cell suppressive capability, in part due to elevated CD101 expression and attenuated pro-inflammatory activities. Thus, our study reveals a mechanism by which neutrophil plasticity and heterogenicity are regulated in colitis through WNT5 and highlights the role of splenic neutrophil production in shaping inflammatory outcomes.

Esplenectomía por tumor hematopoyético extramedular esclerosante del bazo / Splenectomy for sclerosing extramedullary hematopoietic tumor of the spleen

RESUMEN Los tumores hematopoyéticos extramedulares son infrecuentes; se caracterizan por la presencia de elementos formes de la sangre en distintas etapas madurativas, con megacariocitos atípicos y proliferación fibroblástica. Se comunica el caso clínico de un tumor hematopoyético extramedular esclerosante del bazo en un varón de 71 años, con antecedentes patológicos de hipertensión, diabetes, portador de virus hepatitis C. En estudio por malestar abdominal se identificaron mediante imágenes lesiones esplénicas múltiples. Se planteó origen vascular, sin poder descartar otro tipo de lesiones, por lo que se decidió esplenectomía laparoscópica. El estudio histopatológico e inmunohistoquímico diagnosticó un tumor hematopoyético extramedular esclerosante del bazo. Son neoplasias de baja incidencia y escasa evidencia en cuanto a etiopatogenia, diagnóstico y tratamiento. Se presentan como lesiones únicas o múltiples, y pueden afectar diferentes órganos. Están asociados a síndromes mieloproliferativos crónicos. Solo su confirmación histopatológica permite diferenciarlos de otros tumores malignos.

ABSTRACT Extramedullary hematopoietic tumors are rare and characterized by the presence of hematopoietic elements at various stages of maturity, atypical megakaryocytes, and fibroblastic proliferation. We report the case of a patient with sclerosing extramedullary hematopoietic tumor of the spleen.The patient was 71-year-old man with a history of hypertension, diabetes, and hepatitis C virus infection. Multiple spleen lesions were identified in imaging tests during workup due to abdominal discomfort. Although a vascular tumor was suspected, laparoscopic splenectomy was decided after considering other possible causes. The pathology examination revealed a sclerosing extramedullary hematopoietic tumor of the spleen, which was confirmed by immunohistochemical tests. These tumors are usually single or, less frequently, multiple lesions affecting different organs and are associated with chronic myeloproliferative syndromes. The histologic confirmation is mandatory due to their similarity to malignant tumors. Extramedullary hematopoietic tumors are rare, and there is little scientific clinical evidence regarding their diagnosis and management. The histological confirmation is mandatory due to their similarity to malignant tumors.

[Pathogenesis and Targeted Treatment Progress of Splenomegaly in Primary Myelofibrosis--Review].

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm with splenomegaly as the major clinical manifestation, which is commonly considered to be linked to splenic extramedullary hematopoiesis. Alteration of CXCL12/CXCR4 pathway can lead to the migration of hematopoietic stem cells and hematopoietic progenitor cells from bone marrow to spleen which results in splenic extramedullary hematopoiesis. In addition, low GATA1 expression and the abnormal secretion of cytokines were found to be significantly associated with splenomegaly. With the application of JAK1/2 inhibitors in clinical, the symptoms of splenomegaly have been significantly improved in PMF patients. This article will review the pathogenesis and targeted treatment progress of splenomegaly in PMF.

Splenic torsion in a cat with chronic anemia.

Case summary: A 4-year-old female spayed domestic shorthair cat with chronic anemia was evaluated for acute-onset lethargy, vomiting, abdominal distension, and a palpably enlarged and firm spleen. Abdominal ultrasound confirmed marked splenomegaly and concern for a splenic infarct, prompting exploratory abdominal surgery, where splenic torsion was diagnosed. A splenectomy was performed, and the cat recovered uneventfully. Splenitis was diagnosed on histopathology. Anemia improved postoperatively. The role of chronic anemia and other concurrent findings in the development of splenic torsion in this case remains unknown. Relevance and novel information: Splenic torsion has not been previously reported in cats, making this the first case of its kind. In cases of splenomegaly and abnormal splenic blood flow, splenic torsion should be considered a differential diagnosis in cats.

Synovial extramedullary hematopoiesis in a dog.

OBJECTIVE: Synovial extramedullary hematopoiesis is a rarely reported condition in humans and, to date, has never been reported in canines. This case report describes the clinical presentation, diagnostic work-up, treatment, and outcome of a canine case confirmed to have hematopoietic tissue within multiple joints. ANIMAL: A client-owned canine. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The clinical presentation was most consistent with immune-mediated polyarthritis, and arthrocentesis was performed in multiple joints for cytological evaluation and culture. Cytology revealed evidence of extramedullary hematopoiesis, and shortly thereafter the dog was diagnosed with immune-mediated hemolytic anemia and thrombocytopenia. TREATMENT AND OUTCOME: Pregabalin, prednisolone, clopidogrel, and cyclosporine were started, and after several recheck appointments and dose adjustments, the dog's clinical signs resolved for all conditions. CLINICAL RELEVANCE: Unusual sites of extramedullary hematopoietic tissue may result in a clinical presentation for which more traditional etiologies and differentials are not applicable.

Hidden in the mediastinum: a case of extramedullary hematopoiesis unveiled through thoracoscopy.

Extramedullary hematopoiesis (EMH) is a rare condition characterized by proliferation of hematopoietic stem cells outside the bone marrow, usually as a compensatory response to hematological disease. Although EMH primarily occurs in the liver and spleen, it can manifest in atypical locations, such as the mediastinum. We herein describe an asymptomatic 66-year-old man with incidentally discovered posterior mediastinal EMH. A 28- × 32-mm mass was detected during a routine examination. Laboratory findings were within normal limits. Computed tomography revealed a well-defined enhancing mass with a density of 60 Hounsfield units, suggestive of a neurogenic tumor. Surgical resection confirmed EMH, characterized by megakaryocytes and hematopoietic precursors. The patient recovered smoothly and was discharged 5 days postoperatively. Accurate preoperative diagnosis of EMH is challenging, as illustrated by this case. Although typically associated with anemia or hematological abnormalities, EMH can present without such signs. Surgical resection and histopathological examination are essential for diagnosis. This case emphasizes the diagnostic complexity of posterior mediastinal EMH, even in patients without overt hematological disorders. Posterior mediastinal EMH is exceedingly rare and diagnostically demanding. A high index of suspicion and histological tissue analysis are crucial for optimal management. Video-assisted thoracoscopic surgery enables both diagnosis and treatment through mass excision.