Background: Yeast with pseudohyphae or those that have been phagocytized by white blood cells are coincidentally found in peripheral blood smears. The clinical diagnostic value and outcome of candidaemia diagnosed from peripheral blood smears (CPBSs) are unclear.
Case presentation: A 45-year-old man with diabetes and panhypopituitarism for 20 years received 10 mg of hydrocortisone and 100 μg of levothyroxine sodium hydrate daily. He has been admitted seven times because of adrenal failure triggered by infections and was admitted for pneumonia. On day 56, some budding yeast was found microscopically in a peripheral blood smear with May-Giemsa staining. Some of them were phagocytized by white blood cells. The two blood cultures yielded Candida parapsilosis. Despite antifungal treatment and removal of an intravenous catheter, on day 98 (42 days after the candidaemia diagnosis), the patient died.
Conclusion: We analysed 36 cases including the present case. Almost all CPBS patients (96.5 %, n = 29) were using an intravenous catheter. The most frequently isolated species was C. parapsilosis (35.1 %), followed by C. albicans (29.7 %). The overall mortality rate was 53.6 % (n = 28). The time from the discovery of yeast-like pathogens using peripheral blood smears to death ranged from a few hours to 93 days (median 19 days). The present results suggest that intravenous catheter use and the underlying conditions of patients are responsible for CPBSs. The detection of yeast in peripheral blood smears suggests advanced infections with uncontrollable complications, which means a poor prognosis. Rapid detection methods besides blood culture are needed.