INTRODUCTION Essential thrombocythemia (ET) is a myelodysplastic syndrome that constitutes an infrequent cause of ischemic stroke. Few clinical reports have been published describing the clinical onset of ET in the form of a vascular accident.

CASE REPORT We describe four cases of patients with no known haematological pathology who began with an ischemic stroke and were later diagnosed as suffering from ET, following an aetiological investigation. The patients were all young, under 45 years of age, with no significant vascular risk factors, who presented a clinical picture of ischemic stroke and platelet counts above normal values, although in two cases they were below 600 × 109/L. As they progressed, their platelet counts were constantly above this threshold and a diagnosis of ET was reached. Conclusions. Although ET is an infrequent cause of ischemic stroke, it must be taken into account even in young patients and when platelet counts do not exceed 600 × 109/L. Antiplatelet drug therapy must be indicated in all cases and the clinician must evaluate the suitability of cytoreductive therapy in patients with a high risk of thrombotic event recurrence, especially if platelet counts are above 600 × 109/L.

Introducción La trombocitemia esencial (TE) es un síndrome mielodisplásico que constituye una causa infrecuente de ictus isquémico. Hay escasas descripciones clínicas de debut clínico de una TE en forma de accidente vascular agudo.

Casos clínicos Se presentan cuatro casos de pacientes sin patología hematológica conocida que debutan con un accidente vascular cerebral isquémico y en los que la investigación etiológica llevó al diagnóstico de TE. Se trata de pacientes jóvenes, menores de 45 años todos ellos, sin factores de riesgo vascular significativos, que presentan clínica de ictus isquémico y cifras de plaquetas por encima de lo normal, aunque en dos casos por debajo de 600 × 109/L. En la evolución de todos ellos las cifras de plaquetas superaron ese umbral de forma mantenida y se llegó al diagnóstico de TE.

Conclusiones Aunque la TE es una causa infrecuente de accidente vascular cerebral isquémico, debe tenerse en cuenta incluso en pacientes jóvenes y cuando las cifras de plaquetas no superen las 600 × 109/L. Se debe indicar el tratamiento antiagregante en todos los casos y valorar el tratamiento citorreductor en pacientes de alto riesgo de recidiva de fenómenos trombóticos, fundamentalmente si las cifras de plaquetas superan las 600 × 109/L.