The cavity walls and the projections were composed of two rows of epithelial cells showing the sign of decollation secretion.

• 皮肤组织病理检查示部分表皮下陷形成囊腔样结构,囊腔内有许多乳头状突起,囊壁及乳头状突起由两排细胞构成,可见断头分泌;