Extreme Leukocytosis in a Man after a Half Marathon Race

Abstract

Leukocytosis is most often defined as an elevated white blood cell count greater than 11.0 × 109 per L in adults, and is a relatively common finding. Normal adult levels of leucocytes is 4.5 to 11.0 × 109 per L. It is of importance for clinicians to be able to distinguish nonmalignant from malignant conditions, and to differentiate between the most common non-malignant causes of leukocytosis. Extreme leukocytosis can be seen in a broad spectrum of clinical conditions in the human body under stress. It is most commonly found in patients suffering from leukemia or severe bacterial infections, but can also be seen in people after hard exercise [1-7]. The present clinical case describes a young healthy man, suffering from extreme leukocytosis after a syncope during a half marathon.