Multiple orthokeratinized odontogenic cysts: a case report

Abstract

The purpose of this report is to document the clinical, radiographic, pathological and molecular findings of the first case of multiple orthokeratinized odontogenic cysts (OOCs). Multiple odontogenic keratocysts are one of the major features of nevoid basal cell carcinoma syndrome (NBCCS), and loss of heterozygosity in the PTCH gene, the culprit gene for NBCCS, has recently been found in sporadic OOC cases. Therefore, in this presenting case, we also investigated the possibility that this patient might also have NBCCS, by comparing the available clinical information and the molecular findings of this case to the diagnostic criteria for NBCCS (as proposed by the First International Colloquium on NBCCS in 2011). However, this patient with multiple OOCs showed no evidence of having NBCCS. This conclusion supports the findings from previous case series based on sporadic cases that OOC does not appear to be associated with NBCCS.

Fig. 1

Panoramic radiograph showed four well-defined unilocular radiolucent lesions associated with the third molars in all four quadrants: around apex of #1, around the crown of impacted #16, distally and superiorly to impacted #17 and distally to impacted #32, respectively (a). A coronal reformatted CT image revealed a cystic lesion superiorly to #1 with displaced sinus floor in the right maxilla; and a large cystic lesion encompassing the un-erupted #16 in the left maxillary sinus with osseous discontinuity of the left maxillary sinus floor (b). Another coronal CT image showed a cystic lesion associated with the un-erupted #32 at the buccal surface, with thinning of the buccal cortex, and perforation of the superior border in the right mandible; and a large cystic lesion with expansion and thinning of buccal and lingual cortices in the left mandibular ramus (c)

Fig. 2

Histologically, all four lesions showed a cyst with a thin, uniform lining of squamous epithelium (a, H&E stain, original magnification ×28). Orthokeratin formation and a granular cell layer were noted in the cyst lining epithelium (b, H&E stain, original magnification ×140)