Treatment

Under IV sedation, the area was dissected and cortical bone removed to reveal a large cystic cavity partially filled with white cheesy material. The cavity was thoroughly curetted and the specimen submitted for histological evaluation. The surgical area was thoroughly irrigated and the soft sutured. The patient was placed on Percocet. The patient healed with no complications.

Incisional Biopsy

The excisional biopsy demonstrated multiple fragments of soft tissue made up of a cystic cavity lined by keratinized epithelium and surrounding by fibrous connective tissue wall (Figure 2).  The lining epithelium is uniformly thin and corrugated and covered by parakeratin and orthokeratin.  The basal cell layer shows evidence of focal palisading and reverse polarization (Figures 3 & 4).  The lumen is focally filled with keratin (Figure 5).   

Figure 2 Low power (x40) histology shows a fragmented cystic structure with keratinized lining epithelium and connective tissue wall and keratin in the lumen.

Figure 3 Higher power (x100) histology shows a uniformly thin, corrugated and keratinized lining epithelium with palisaded basal cell layer.

Figure 4 Higher power (x200) histology shows closer magnification of the palisaded basal cell layer with focal reversed polarization.

Figure 5 Low power (x100) histology shows a fragmented cystic structure with keratinized lining epithelium and keratin in the lumen.