Refractory Human Cutaneous Protothecosis.

A 67-year-old Scottish woman presented to her general practitioner with a subcentimeter lump between her shoulder blades. The lump was suspected to be an epidermal cyst and was excised. The patient had a history of controlled diabetes. Most summers, she spent a month near a beach resort in Mexico. The lump reappeared after 6 months within the scar area and was re- excised. Both skin excisions were performed in the primary care setting without histologic assessment.