JAK2-positive erythrocytosis presenting with left occipital infarction in a young adult: a case report from a resource‑limited setting.

Introduction: Polycythemia-spectrum disorders carry thrombotic risk; in young adults, stroke may be the first manifestation. We report a young male with JAK2-positive erythrocytosis highly suggestive of polycythemia vera, emphasizing diagnostic framing and pragmatic management in a resource-limited setting. Case presentation: A 35-year-old former smoker presented with three days of right-sided body tingling. Examination was nonfocal. Laboratory testing revealed hemoglobin 19.3 g/dL and hematocrit 61.4%. Noncontrast computed tomography obtained on Day 3 showed a small, ill-defined hypodensity in the left occipital lobe, consistent with acute infarction. JAK2 V617F mutation was detected; erythropoietin (EPO) was within the normal range (20 mU/L). In the absence of marrow histology and subnormal EPO, the working diagnosis was JAK2-positive erythrocytosis with a syndrome highly suggestive of PV. Treatment comprised phlebotomy, low-dose aspirin, hydroxyurea, and statin therapy. Discussion: The case highlights pragmatic stroke evaluation in a young adult, where MRI and comprehensive vascular work-up were not fully available. We discuss pathophysiology, differential diagnoses, and how resource constraints impact certainty and generalizability. Conclusion: Ischemic stroke can be the initial presentation of JAK2-positive erythrocytosis consistent with polycythemia vera. Careful framing of diagnostic certainty, early hematocrit control, antithrombotic therapy, and risk-factor optimization are key, especially where resources are limited.