Platelet satellitism is a rare condition of not very frequent description and exclusively in vitro in EDTA treated blood samples, and it is not associated with any clinicas manifestation. The phenomenon consist in the finding of platelet around polymorphonuclear (PMN) leucocytes forming a kind of rosettes. Recently two cases of platelet satellitism were describes in Costa Rica. That report aimed to describes a third case recentiy appeared in this country. The patient is an adult man of  21 years old, without any manifestad pathological signs. Peripheral blood smears made each one or two hours form an EDTA treated blood sample kept at room temperature for 12 hours were analysed. The platelet satellitism was exacerbase in the smears made from 2 to 6 hours, because more than 90% of the PMN appeared forming platelet rosettes. Then, this frequent down at less than 50%. The finding of the third case from Costa Rica in a relatively short time, race the suspicious that platelet satellitism couid be a more frequent phenomenon than is deduced from the medical literatura reports.

Platelet satellitism; anticoagulant EDTA