Odontogenic keratocyst in geriatric population: a developmental cyst in elderly patients

Introduction
Odontogenic keratocyst (OKC) was rarely reported in geriatric population. To the best of our knowledge, only 15 cystic cases, of which one radiograph was documented, and eight solid OKCs were reported in geriatric patients.

Objectives
This study investigated the difference between the histological and immuno-histochemical profile of juvenile and geriatric cases of sporadic OKC.

Material and methods
In this retrospective study, a control group of 15 sporadic juvenile OKCs (group 1), 15 juvenile syndromic OKCs (group 2), and 15 juvenile recurrent OKCs (group 3) patients were included and clinico-pathologically compared with newly reported cases. Group 4 was composed of three geriatric cases only. Paraffin wax blocks were sectioned to be stained with anti-NPM1/ALK (Abcam), anti-CK7, anti-CK14, anti-Ki-67, anti-SOX-10, and anti-Cyclin D1 in all groups. One-way ANOVA test was used to compare the studied groups.

Results
The difference between immuno-staining for anti-NPM1/ALK, anti-CK7, anti-CK14, anti-Ki-67, anti-SOX-10, and anti-Cyclin D1 was not statistically significant. Therefore, the nature of OKC in the geriatric population did not differ from that of the younger population, posing strong controversy about classifying OKCs as only developmental lesions.

Conclusions
True sporadic odontogenic keratocyst can affect geriatric populations, which defies the general theoretical consensus about the developmental origin of sporadic OKCs. This is complicated by the fact that the proliferation index is high in geriatric and juvenile populations.