Under local anesthesia, a full-thickness flap around the area was raised and the lesion enucleated in one piece (Figure 3) and the cavity was thoroughly curetted as shown in the composite Figure 3. The area was sutured and the specimen submitted for microscopic evaluation.

Figure 3 This is a composite figure representing the surgical flap followed by the clinical appearance of the lesion after the bone was exposed, followed by enucleation of the lesion which was removed intact in one piece.

Excisional Biopsy

Histologic examination reveals a multisected piece of soft tissue composed of a cystic structure lined by epithelium and supported by a fibrous connective tissue wall (Figures 4-6). The lining epithelium is uniformly thin and is slightly corrugated. It is covered by parakeratin. Some of the latter is present in the lumen of the cyst. The basal cell layer is focally palisaded (Figure 6). The connective tissue wall is fibrotic and thin in most parts. It is focally infiltrated by a few lymphocytes and plasma cells.

Figure 4 Low power (x40) H & E histology illustrates a cystic structure lined by keratinized stratified squamous epithelium supported by connective tissue wall.

Figure 5 Higher power (x200) H & E histology illustrates a higher power of the cyst lining epithelium where it is corrugated and covered by a thin layer of parakeratin.

Figure 6 Higher power (x200) H & E histology illustrates a higher power of the lining epithelium demonstrating a palisaded basal cell layer.