Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 10 3 2025 12 09 93 97 Mahtab Ghaemi Department of Internal Medicine, Birjand University of Medical Sciences, Birjand, Iran. 2025 06 11 2025 07 30 This case report describes a middle-aged female with untreated hypertension who was released from the hospital with signs and symptoms of sharp pleuritic chest pain, with a concern for a cardiac issue. Following the concern for a cardiac diagnosis, diagnostic testing determined profound ST elevations across the ECG, severe anemia (hemoglobin 9.6 g/dL), and inflammatory activity (ESR 93 mm/hr, CRP 77.7 mg/L), with high LDH (2185 U/L). There was evidence on imaging of left atrial enlargement, hepatosplenomegaly, liver lesions, and mineralized bone changes, with myelofibrosis (MF) confirmed through marrow biopsy showing marrow fibrosis and atypical megakaryocytes. This case illustrates the diagnostic considerations of MF, which can present with various differential diagnoses. Treatment of the patient consisted of managing symptoms with aspirin; the possible options of treatment included longterm therapy with a JAK2 inhibitor or stem cell transplant. This case underscores the importance of considering MF in patients with unexplained cytopenias, splenomegaly, and systemic inflammation. https://crcp.tums.ac.ir/index.php/crcp/article/view/1056 https://crcp.tums.ac.ir/index.php/crcp/article/download/1056/725