ABSTRACT NUMBER: ESOC2026A2274 ISCHEMIC STROKE IN A PATIENT WITH SECONDARY POLYCYTHEMIA – A CASE REPORT

Abstract Background and aims Ischemic stroke (IS) in the setting of erythrocytosis is classically associated with polycythemia vera and a thorough diagnostic work-up to exclude myeloproliferative neoplasms is essential. We report a case of a 74-year-old female with IS and marked secondary erythrocytosis after comprehensive exclusion of myelodysplastic/myeloproliferative etiologies, highlighting plausible contributory mechanisms and clinical considerations. Methods case report Results The patient, with a history of obesity, diuretic-treated arterial hypertension, COPD, smoking (110 pack years), presented with a 2-day history of gait instability, right homonymous hemianopia with macular sparing, dysarthria, right hemiparesis and hemisensory loss. Neuroimaging was consistent with an ischemic stroke in the left PCA territory. Complete blood count demonstrated erythrocytosis (red blood cell count 6.19 Μ/μl, hemoglobin 20.9 gr/dL and hematocrit 61.6%). Hematologic investigation of myelodysplastic syndromes was negative: no pertinent signs / symptoms, non-suppressed serum erythropoietin, no genetic mutations detected (V617F/JAK2, EPO-R, exon 12 of JAK2), including no abnormalities on karyotype analysis of bone marrow cells. Bone marrow aspiration and trephine biopsy were negative for MDS pathology. Immunologic and malignancy work-up were insignificant. The erythrocytosis was attributed to chronic hypoxemia and hypercarbia due to obesity-related central hypoventilation and sleep apnea syndrome, smoking, COPD, renal cysts and chronic diuretic use. Conclusions IS in secondary polycythemia has been sporadically described; this is the first case of multifactorial secondary polycythemia in the context of IS. Potential mechanisms include hyperviscosity, disturbed red blood cell morphodynamics, endothelial dysfunction, platelet/leukocyte disruption and coexisting vascular risk factors. Conflict of interest Konstantinos Ntoskas: nothing to disclose - Dimitrios Christoulas: nothing to disclose - Panagiotis Petrikkos: nothing to disclose