Epidermoid cysts are classified benign skin tags requesting only elective surgery. But there are reports in the literature showing life-threatening courses as well.
While visiting her homeland a 9.5 y old girl started shivering and getting feverish. She was admitted to the rural hospital where symptomatic treatment started. Since her condition worsened she was repatriated. On arrival she was septic and somnolent. Plane x-rays revealed a small bony channel beyond the clinically identified epidermoid cyst; confirmed in detail on high solution CT scan together with an increasing hydrocephalus internus. In an emergency procedure external shunting was performed. After ICB decrease the child could be weanded off the ventilator but left hemiparesis and cortical blindness were persistent. An osteoplastic occipital craniotomy was performed and the entire cyst, originating from the brain stem, removed. Due to enhanced liquor production and drainage an ETV to improve interventricular flow was performed. But despite a visible outflow in MRI scans unfortunately no remarkable clinical improvement resulted requiring a classical VP-shunt. After stabilization of her vitals intensive neuro-rehabilitation started. The girl made good progress, in 1-year follow-up only slight deficits have to be considered.
In conclusion, epidermal cysts rarely cause encephalo-mengingitis but if they do they are always life-threatening and restitutio ad integrum is not certain.