proliferating trichilemmal cyst (pilar tumor of the scalp)
Histologic Features
- A well-circumscribed dermal cystic structure characterized by
- Folded eosinophilic lobules of cornifying squamous epithelium with palisaded peripheral basaloid layers, eosinophilic horn pearls and squamous eddies in the inner layers
- A moderate degree of nuclear atypia
- Eosinophilic amorphous keratin with focal calcification within the cyst content
- Palisade of smaller cells at the periphery with adjacent basement membrane
- Focal sebaceous or germinative differentiation
Updated Wednesday, July 31, 2013 8:30:48 PM