[Perforating and ruptured trichilemmal cyst with metaplastic ossification]. / Perforierende rupturierte Trichilemmalzyste mit metaplastischer Ossifikation.

Trichilemmal cysts can occur as multiple scalp lesions and may have a familial history. Metaplastic ossification, as seen in several traumatic, inflammatory or neoplastic conditions, however, seems to be an exceedingly rare event in trichilemmal cysts and might be associated with previous rupture.