Ethnic sensitivity analyses of pharmacokinetics, efficacy and safety in polycythemia vera treatment with ropeginterferon alfa-2b.

Ropeginterferon alfa-2b (Ropeg) is approved for the treatment of adults with polycythemia vera (PV). This report aims to analyze the ethnic sensitivity of Ropeg for the treatment of PV, comparing the pharmacokinetics (PK), efficacy, and safety profiles across diverse ethnic groups. We conducted a relevant review of PV and analysis of data obtained from clinical studies involving Ropeg. The PK behavior of ropeg showed no significant differences between Chinese and overseas populations. Their efficacy and safety profiles were similar across the ethnic groups. The analyses indicated that the dose-exposure-response profile of Ropeg was consistent irrespective of ethnic variations. The results suggest that Ropeg exhibits a consistent PK and pharmacodynamics profile and a similar therapeutic effect across different ethnic groups, confirming its efficacy and safety in the global treatment of PV. More generally, these findings support the broader application of Ropeg in diverse patient populations and emphasize the need for an inclusive clinical practice.

Efficacy and safety of ruxolitinib vs best available therapy for polycythemia vera: An updated systematic review and meta-analysis.

Ruxolitinib, a JAK1/JAK2 inhibitor, has been shown to have lower thromboembolism rates compared to placebo in polycythemia vera (PV) patients. This meta-analysis evaluates ruxolitinib's efficacy and safety against best available therapy (BAT) in patients with PV and in hydroxyurea-resistant/intolerant PV patients. A comprehensive literature search was conducted up to November 2023. We compared ruxolitinib and BAT for efficacy and safety endpoints. Six studies involving 1061 patients were analyzed, with 620 on BAT and 441 on ruxolitinib. Ruxolitinib showed higher hematocrit control (p = 0.015) and treatment response (p = 0.04) compared to BAT. It also significantly improved Myeloproliferative Neoplasms-Symptom Assessment Form scores (MPN-SAF) (p < 0.01). Additionally, patients with PV treated with ruxolitinib had higher rates of nonmelanoma skin cancer (p < 0.01). In subgroup analyses focusing on patients resistant or intolerant to hydroxyurea, ruxolitinib maintained its efficacy, significantly improving treatment response (p < 0.01) and significant improvements in MPN-SAF (p = 0.02) score when compared to BAT. The safety profile was consistent with the overall analyses, showing significantly reduced thromboembolism rates (p = 0.04), increased rates of anemia (p = 0.01), and increased herpes zoster infections (p = 0.02). Ruxolitinib outperforms BAT in PV and patients with PV-resistant or intolerant to hydroxyurea, offering better hematocrit control and reducing symptomatic burden and thromboembolism risk. Yet, it is associated with higher rates of anemia, herpes infection, and skin cancer.

A Case of Renal Artery Thrombosis With Concurrent Adrenal Hemorrhage in Polycythemia Vera.

Polycythemia vera (PV) is a rare myeloproliferative neoplasm characterized by the clonal proliferation of hematopoietic stem cells, leading to an elevated red blood cell mass. This hyperproliferative state increases blood viscosity and predisposes patients to thrombotic events, which are a significant cause of morbidity and mortality in PV. The diagnosis of PV is typically confirmed through elevated hemoglobin or hematocrit levels, low serum erythropoietin, and the presence of the Janus kinase 2 (JAK2) mutation. Common complications include venous and arterial thromboses, hemorrhage, and transformation to myelofibrosis or acute leukemia. A 68-year-old female with a history of PV and chronic kidney disease (CKD) presented with uremic symptoms in the form of malaise and nausea. Laboratory investigations indicated acute kidney injury (AKI) and hyperkalemia. Imaging evaluation of renal US Doppler revealed renal artery thrombosis and an incidental adrenal hemorrhage. The patient was managed with intravenous heparin and did not receive thrombolytics or thrombectomy. Her renal function did not improve, necessitating the initiation of hemodialysis (HD) during hospitalization. Over the course of the next few weeks, her renal parameters improved and she managed to be discharged from dialysis. The primary goal of this study was to highlight a rare presentation of renal artery thrombosis secondary to polycythemia vera (PV) and discuss the complexities involved in managing the underlying disease and its thrombotic complication, particularly in the presence of concomitant bleeding. Effective management of PV-related thrombosis requires a delicate balance between anticoagulation to prevent further thrombotic events while carefully addressing the risk of hemorrhage.

Long-term safety and efficacy of ropeginterferon alfa-2b in Japanese patients with polycythemia vera.

Ropeginterferon alfa-2b (ropegIFN), a new-generation interferon-based agent, has been approved in Japan for patients with polycythemia vera (PV) who are ineligible for or respond inadequately to conventional treatment. However, long-term outcomes with ropegIFN in Japanese patients have not been reported. This extension of a phase 2 study of ropegIFN in Japanese patients with PV aimed to determine its long-term safety/efficacy, and changes over time in JAK2 V617F allele burden. Here, we report data from the phase 2 study and subsequent extension over a period of 36 months. The primary endpoint was the complete hematologic response (CHR) maintenance rate without phlebotomy (hematocrit value < 45% without phlebotomy during the previous 12 weeks, platelet count ≤ 400 × 109/L, and white blood cell count ≤ 10 × 109/L). The CHR maintenance rates were 8/27 (29.6%), 18/27 (66.7%), and 22/27 (81.5%) at 12, 24, and 36 months, respectively. No thrombotic or hemorrhagic events occurred. The median allele burden change from baseline was - 74.8% at 36 months. All patients experienced adverse events; 25/27 (92.6%) experienced adverse drug reactions (ADRs), but no serious ADRs or deaths occurred. This interim analysis demonstrated the safety and efficacy of ropegIFN over 36 months in Japanese patients with PV.

Dental Implant placement in a patient with polycythemia vera: A case report.

Polycythemia vera is a malignant myeloproliferative neoplasm. It is characterized by the proliferation of all three major hematopoietic cells, including erythrocytes, leucocytes, and platelets. The resultant hypervolemia and hyperviscosity cause patients with polycythemia vera to be at risk of bleeding and thrombotic complications. This article reports a rare case in which a patient with preexisting polycythemia vera at a dental clinic underwent dental implant placement and provides the possibility of dental implant placement with an excellent outcome for patients with polycythemia vera.

Treatment of the blood cancer polycythemia vera with ruxolitinib in the MAJIC-PV study: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of an article describing the main results of the MAJIC-PV study. This study looked at using the cancer drug ruxolitinib to treat a type of blood cancer called polycythemia vera. People with polycythemia vera make too many red blood cells in their body. This can make their blood thicker and can increase the chances of blood clots forming in their blood vessels.Researchers wanted to find out how well ruxolitinib worked compared with the best available therapy as a treatment for people with polycythemia vera who were at risk of developing blood clots that could lead to a heart attack or stroke. Specifically, the study looked at people who had already taken the chemotherapy hydroxycarbamide (also known as hydroxyurea) for their polycythemia vera, but it either didn't work for them or gave them side effects that they could not tolerate. WHAT WERE THE RESULTS?: In the study, researchers divided 180 adults with polycythemia vera who were at high risk of developing blood clots that could lead to a stroke into two groups: 93 people who took ruxolitinib twice a day, and 87 people who took the best available therapy. 43% of people who took ruxolitinib and 26% of people who had the best available therapy had normal blood counts and spleen size within 1 year of treatment. 84% of people who took ruxolitinib and 75% of people who had the best available therapy lived for at least 3 years without their polycythemia vera becoming a more advanced type of blood cancer. The most common side effects were disorders of the digestive system (stomach and gut), disorders of the blood vessels, and infections. This is similar to the side effects that doctors know about for ruxolitinib. WHAT DO THE RESULTS MEAN?: Compared with people who had the best available therapy for their polycythemia vera, people who took ruxolitinib were more likely to have normal blood counts and spleen size within 1 year of treatment, and were more likely to live longer without their polycythemia vera becoming a more advanced type of blood cancer.

Treatment of Twin Anemia Polycythemia Sequence with Donor Transfusion and Partial Recipient Exchange Transfusion: Procedural Considerations and Outcomes.

Background: Intrauterine transfusion (IUT) of the donor and partial exchange (pET) of the recipient is a temporizing treatment for pregnancies with Twin Anemia Polycythemia Sequence (TAPS). We aimed to provide a detailed description of the procedural approach and outcomes for sequential donor IUT and recipient pET in TAPS. Methods: Retrospective study of spontaneous TAPS referred to the Johns Hopkins Center for Fetal Therapy treated with donor IUT followed by recipient pET utilizing a double-syringe setup. Procedural characteristics and outcomes as well as the accuracy of existing transfusion formulas were analyzed and compared with the literature. Results: 5 of 78 patients with spontaneous TAPS underwent a total of 19 combined IUT/pET procedures (median first procedure to delivery interval 5.6 weeks [interquartile range IQR 1.9-6.0]). One pET was stopped due to fetal deceleration. The patients were delivered at 33.0 weeks [IQR 31.9-33.3] with two survivors and no neonatal transfusion requirements. The IUT volume was 48 mL [IQR 39-63 mL] and the pET volume was 32 mL [IQR 20-50], utilizing aliquots of 5-20 mL for the latter (p = 0.021). For the IUTs, the assumption of a fetal blood volume below 150 mL/kg underestimated the required transfusion volume. For the pETs, all formulas required adjustment of the dilution volume based on bedside testing (p < 0.05 for all). Conclusions: Donor transfusion followed by partial exchange in the recipient can prolong pregnancy in spontaneous TAPS and obviate the need for neonatal transfusion. A double-syringe setup facilitates efficient saline exchange. Because the accuracy of volume formulas is limited, bedside testing is recommended to achieve the target hemoglobin.

Response, complications and risk of leukemic transformation of phosphorus-32p treatment in philadelphia-negative chronic myeloproliferative syndromes.

OBJECTIVE: Describe our experience in treatment with Phosphorus-32P for refractory Philadelphia negative chronic myeloproliferative syndromes or with side effects to the usual treatment, its complications and risk of leukemic transformation. MATERIAL AND METHODS: Retrospective descriptive study including 17 patients with a diagnosis of Philadelphia-negative chronic myeloproliferative syndrome treated with Phosphorus-32P in our hospital from January 1985 to March 2017. Indications, response to treatment, as well as early and late complications have been analyzed. RESULTS: Of the 17 patients treated with 32P (11 men, 6 women; mean age 79,8 years), 6 patients had Polycythemia Vera and 11 Essential Thrombocytosis. A single dose was administered in 9 of the subjects, the rest required two or more doses due to inadequate hematological response and/or relapse. The total dose range of Phosphorus-32P administered was 116-951 MBq (median: 236 MBq). In 14 patients treated with Phosphorus-32P, complete or partial response was achieved in hematimetry. In 11 patients, the response was complete, established as a platelet count <400.000/mm3 in those diagnosed with Essential Thrombocythemia and a hematocrit <45% in cases of Polycythemia Vera. The median follow-up of patients from the date of the first treatment of Phosphorus-32P until study completion or death was 37 months (range: 5-230 months). Regarding early complications, 2 cases of anemia requiring blood transfusion were observed, and 1 case of mild thrombocytopenia. No leukemic transformation was identified. CONCLUSIONS: In our experience, treatment with Phosphorus-32P has been a useful therapeutic option in Philadelphia-negative chronic myeloproliferative syndromes in elderly patients who showed poor tolerance and/or resistance to first-line treatment. No leukemic transformation was identified.

[Treatment strategies for low-risk polycythemia vera].

Treatment selection for patients with polycythemia vera (PV) is based on patient age and history of thrombosis. The standard treatment is low-dose aspirin and phlebotomy for low-risk PV, with cytoreductive therapy added for high-risk PV. Thrombotic events and disease progression due to PV clone expansion affect the prognosis of PV. Although phlebotomy is effective in controlling hematocrit level, it has no effect on disease progression or PV-related symptoms. In Western countries, interferon (IFN) has been used as a cytoreductive therapy for PV. Long-term IFN therapy has been shown to result in sustained hematologic remission and molecular responses. Ropeginterferon-α-2b (ropeg-IFN), which is administered every two weeks, has recently become available. Clinical trials in patients with PV have shown that ropeg-IFN treatment is safe and efficacious, reducing JAK2V617F allele burden. Ropeg-IFN could ultimately affect long-term hematologic remission and molecular response in younger patients with low-risk PV, and may even offer a cure.

Performance and safety of therapeutic erythrocytapheresis in polycythemia and hemochromatosis treatment: single centre experience.

INTRODUCTION: Therapeutic erythrocytapheresis has some advantages over therapeutic phlebotomy, the standard treatment for cytoreduction in polycythemia and hemochromatosis. Erythrocytapheresis can be performed on different cell separators, each with its own characteristics. We present our experience of therapeutic erythrocytapheresis in the treatment of polycythemia and hemochromatosis with an analysis of the performance of cytoreduction, and a comparison between the characteristics of intermittent- and continuous-flow cell separators. MATERIAL AND METHODS: During a 20-year period, 1731 procedures were performed in 125 patients, 1634 (94.4%) with a Haemonetics MCS+ separator and 97 (5.6%) with a Spectra Optia system device. The performance of cytoreduction using the Haemonetics MCS+ separator was analysed in 442 procedures performed in 56 patients and the performance of the two apheresis devices was compared. RESULTS: Haemoglobin (Hb) and haematocrit (Hct) values were significantly reduced after erythrocytapheresis with the Haemonetics MCS+ device (Hb: 18.69%; Hct: 18.73%; p-values both <0.001). The reductions of Hb and Hct were significantly higher in the Haemonetics MCS+ procedure (p-value <0.001), but the Spectra Optia procedure depleted a significantly higher RBC volume (495 mL versus 442 mL) in a shorter time (18 min versus 36 min). CONCLUSION: Both the Haemonetics MCS+ and Spectra Optia systems proved to be highly efficient and safe in RBC cytoreduction with short procedure times. Erythrocytapheresis reduces the frequency of necessary procedures thereby justifying its therapeutic use especially in eligible patients of working age.

[Expert consensus on Tibetan medicine diagnosis and treatment for high altitude polycythemia].

High altitude polycythemia(HAPC) is one of the most common chronic high-altitude diseases and a prominent public health issue in the Qinghai-Xizang Plateau region of China. Tibetan medicine has provided a safe and effective treatment approach for HAPC, but there is currently no expert consensus on Tibetan medicine diagnosis and treatment for the disease. This consensus followed the principles of evidence-based medicine and learned the procedure and methods of Technical specifications on developing expert consensus for clinical practice guideline in traditional Chinese medicine recommended by China Association of Chinese Medicine. Five clinical issues were identified through literature search, expert interviews, clinical research, and conference consensus. The PICO principle was used for evidence retrieval, screening, and synthesis, and the opinions of experts on high-altitude diseases and cardiovascular and cerebrovascular diseases from major Tibetan medical institutions in China, as well as some traditional Chinese medicine(TCM), western medicine, and evidence-based experts, were widely solicited. Recommendations and consensus suggestions were formed through one expert consensus meeting and two rounds of Delphi expert questionnaire surveys. The consensus included disease diagnosis, etiology and pathogenesis, syndrome classification, clinical treatment, outcome evaluation, prevention and care, and other contents. Therapies for HAPC included Tibetan medicine treatments based on syndrome differentiation, single formula or patent medicine, and external treatment. Each treatment had corresponding levels of evidence and recommendations. This consensus was guided by solving clinical problems, combining disease diagnosis and syndrome differentiation and highlighting the characteristics and advantages of Tibetan medicine, with a view to promoting the standardization of Tibetan medicine diagnosis, treatment, and research on HAPC and improving the level of prevention and treatment.

High altitude polycythemia and its maladaptive mechanisms: an updated review.

High altitude polycythemia is a maladaptation of highlanders exposed to hypoxic environment, leading to high blood viscosity and severe cardiorespiratory dysfunction. Prolonged hypoxia causes respiratory depression and severe hypoxemia, and further mediates changes in genetic and molecular mechanisms that regulate erythropoiesis and apoptosis, ultimately resulting in excessive erythrocytosis (EE). This updated review investigated the maladaptive mechanisms of EE, including respiratory chemoreceptor passivation, sleep-related breathing disorders, sex hormones, iron metabolism, and hypoxia-related factors and pathways.

Non-ischemia Cardiomyopathy and Polycythemia Secondary to Anabolic-Androgenic Steroid Use.

Athletes and bodybuilders use anabolic-androgenic steroids (AAS) to increase muscle mass and enhance performance. Its use is widespread among competitive athletes in order to enhance athletic performances. However, the use of AAS has been linked to many deleterious adverse effects, including cardiomyopathy and polycythemia. We present the case of a young man in his late 20s who presented with uncontrolled hypertension and elevated hemoglobin. He was found to have a reduced left ventricular ejection fraction of 20-25%. Further workup showed dilated cardiomyopathy and low normal erythropoietin (EPO) levels. Evaluation for polycythemia vera was negative, and there was no evidence of ischemic cardiomyopathy. The patient later admitted to using injected AAS for professional bodybuilding. The coexistence of both these conditions can be challenging to diagnose and treat. While primary and secondary polycythemia can lead to hyperviscosity and result in ischemic cardiomyopathy from coronary occlusion, anabolic steroids can directly result in cardiomyopathy and polycythemia. This case points to the importance of identifying cardiomyopathy and polycythemia from illicit drug use, which can often be missed, and the workups needed to identify the etiology.

Diagnostic Performance of Serum Erythropoietin to Discriminate Polycythemia Vera from Secondary Erythrocytosis through Established Subnormal Limits.

Serum erythropoietin (sEPO) is an initial screening tool for distinguishing polycythemia vera (PV) from secondary erythrocytosis (SE), but defining 'subnormal' sEPO levels for PV diagnosis remains contentious, complicating its clinical utility. This study compares the diagnostic performance of sEPO across established subnormal limits, including reference interval (RI), clinical decision limit (CDL), and functional reference limit. sEPO levels were analyzed in 393 healthy donors (HDs) and 90 patients (41 PV and 49 SE), who underwent bone marrow biopsy and genetic tests due to erythrocytosis. The RI (2.5-97.5 percentile from HDs) of sEPO was 5.3-26.3 IU/L. A CDL of 3.1 IU/L, determined by ROC analysis in erythrocytosis patients, had a sensitivity of 80.5% and specificity of 87.8% for diagnosing PV. A functional reference limit of 7.0 IU/L, estimated based on the relationship between sEPO and hemoglobin, hematocrit, and WBC, increased sensitivity to 97.6% but decreased specificity to 46.7%. Using 5.3 IU/L as a 'subnormal' limit identified all three JAK2-negative PV cases, increasing the sensitivity and negative predictive value to 97.6% and 97.0%, respectively. Combining the RI, CDL, and functional reference limit may improve PV diagnostic accuracy.

A Rare Case of High-Altitude Polycythemia Complicated by Spontaneous Splenic Rupture.

Wang, Bowen, Mengjia Peng,, Liheng Jiang,, Fei Fang,, Juan Wang,, Yan Li,, Ruichen Zhao,, and Yuliang Wang,. A Rare Case of High-Altitude Polycythemia Complicated by Spontaneous Splenic Rupture. High Alt Med Biol. 25:247-250, 2024.-High-altitude polycythemia, a condition characterized by an increase in red blood cellRBC mass, can occur after prolonged exposure to high altitudes. While several studies have explored the complications associated with high-altitude polycythemia, there is currently no literature available on spontaneous spleen rupture caused by high-altitude polycythemia. Here, we reported a case of acute abdominal pain and hemodynamic instability in a 36-year-old male who had been residing at high altitude for 6 years, without any recent history of trauma. Computed tomography imaging revealed significant fluid accumulation in the abdomen, and a tear of the splenic capsule was identified during the following laparotomy. Subsequent evaluations confirmed the presence of polycythemia secondary to prolonged high-altitude exposure as the underlying etiology. This case served as an important reminder that high-altitude polycythemia could lead to serious complications, such as spontaneous spleen rupture. Clinicians should be aware of this potential complication and consider it in the differential diagnosis of patients presenting with abdominal pain and hemodynamic instability in this population.

Testosterone therapy-induced erythrocytosis: can phlebotomy be justified?

Erythrocytosis, or elevated hematocrit, is a common side effect of testosterone therapy (TTh) in male hypogonadism. Testosterone stimulates erythropoiesis through an initial rise in erythropoietin (EPO), the establishment of a new EPO/hemoglobin 'set point', and a parallel decrease in the master iron regulator protein hepcidin, as well as several other potential mechanisms. Evidence shows an increased thrombotic risk associated with TTh-induced erythrocytosis. Several guidelines by endocrine organizations for the treatment of male hypogonadism recommend against starting TTh in patients presenting with elevated hematocrit at baseline or stopping TTh when its levels cannot be controlled. Besides dose adjustments, therapeutic phlebotomy or venesection is mentioned as a means of reducing hematocrit in these patients. However, evidence supporting the efficacy or safety of therapeutic phlebotomy in lowering hematocrit in TTh-induced erythrocytosis is lacking. In light of this dearth of evidence, the recommendation to lower hematocrit using therapeutic phlebotomy is notable, as phlebotomy lowers tissue oxygen partial pressure (pO2) and eventually depletes iron stores, thereby triggering various biological pathways which might increase thrombotic risk. The potential pros and cons should therefore be carefully weighed against each other, and shared decision-making is recommended for initiating therapeutic phlebotomy as a treatment in patients on TTh who present with increased hematocrit.

The JAK1/JAK2 inhibitor ruxolitinib inhibits mediator release from human basophils and mast cells.

Introduction: The Janus kinase (JAK) family includes four cytoplasmic tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) constitutively bound to several cytokine receptors. JAKs phosphorylate downstream signal transducers and activators of transcription (STAT). JAK-STAT5 pathways play a critical role in basophil and mast cell activation. Previous studies have demonstrated that inhibitors of JAK-STAT pathway blocked the activation of mast cells and basophils. Methods: In this study, we investigated the in vitro effects of ruxolitinib, a JAK1/2 inhibitor, on IgE- and IL-3-mediated release of mediators from human basophils, as well as substance P-induced mediator release from skin mast cells (HSMCs). Results: Ruxolitinib concentration-dependently inhibited IgE-mediated release of preformed (histamine) and de novo synthesized mediators (leukotriene C4) from human basophils. Ruxolitinib also inhibited anti-IgE- and IL-3-mediated cytokine (IL-4 and IL-13) release from basophils, as well as the secretion of preformed mediators (histamine, tryptase, and chymase) from substance P-activated HSMCs. Discussion: These results indicate that ruxolitinib, inhibiting the release of several mediators from human basophils and mast cells, is a potential candidate for the treatment of inflammatory disorders.

Establishment of a nomogram model for predicting therapy complications in patients with polycythemia and deep venous thrombosis.

BACKGROUND: Patients with deep venous thrombosis (DVT) residing at high altitudes can only rely on anticoagulation therapy, missing the optimal window for surgery or thrombolysis. Concurrently, under these conditions, patient outcomes can be easily complicated by high-altitude polycythemia (HAPC), which increases the difficulty of treatment and the risk of recurrent thrombosis. To prevent reaching this point, effective screening and targeted interventions are crucial. Thus, this study analyzes and provides a reference for the clinical prediction of thrombosis recurrence in patients with lower-extremity DVT combined with HAPC. AIM: To apply the nomogram model in the evaluation of complications in patients with HAPC and DVT who underwent anticoagulation therapy. METHODS: A total of 123 patients with HAPC complicated by lower-extremity DVT were followed up for 6-12 months and divided into recurrence and non-recurrence groups according to whether they experienced recurrence of lower-extremity DVT. Clinical data and laboratory indices were compared between the groups to determine the influencing factors of thrombosis recurrence in patients with lower-extremity DVT and HAPC. This study aimed to establish and verify the value of a nomogram model for predicting the risk of thrombus recurrence. RESULTS: Logistic regression analysis showed that age, immobilization during follow-up, medication compliance, compliance with wearing elastic stockings, and peripheral blood D-dimer and fibrin degradation product levels were indepen-dent risk factors for thrombosis recurrence in patients with HAPC complicated by DVT. A Hosmer-Lemeshow goodness-of-fit test demonstrated that the nomogram model established based on the results of multivariate logistic regression analysis was effective in predicting the risk of thrombosis recurrence in patients with lower-extremity DVT complicated by HAPC (χ 2 = 0.873; P > 0.05). The consistency index of the model was 0.802 (95%CI: 0.799-0.997), indicating its good accuracy and discrimination. CONCLUSION: The column chart model for the personalized prediction of thrombotic recurrence risk has good application value in predicting thrombotic recurrence in patients with lower-limb DVT combined with HAPC after discharge.

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.