Protothecosis is a rare infection, which has the potential to cause severe disease in patients with underlying immunosuppression. We describe a case of an elderly female with chronic lymphocytic leukemia (CLL), as well as other risk factors, who presented with pustular and erythematous plaques, initially presumed to be leukemia cutis. A biopsy with special stains revealed the lesions to be cutaneous protothecosis, thus presenting a most unusual concurrence of disease entities. The literature to date on this rare infection will be reviewed.
Keywords: Prototheca wickerhamii; achlorophyllic algae; protothecosis.