Late-Onset of Keratocysts in De Novo Mutation c.1347+1G>A on Intron 9 PTCH1- (NBCCS) – Diagnosis and Therapy

Abstract

Introduction: The occurrence of two main symptoms (calcification of the falx cerebri, odontogenic keratocysts, basal cell carcinoma) and a minimum of one secondary symptom is necessary for de-novo diagnosing a Basal Cell Nevus Syndrome (BCNS). Late diagnosing is usual if the primary symptoms are absent. Subtypes of BCNS may express phenotypes at different ages. Early recognition is needed. The adhesion of keratocysts to the basal bone layer varies, so different treatment options are standard. Aim: A 47-year-old woman without clinical signs of BCNS except macrocephaly suffered from de-novomutation of the PTCH1 gene. Odontogenic keratocysts were recognized sporadically by CB-CT ten years later, as late-onset; Compared to subsequent generations, who often present the main symptoms in childhood. The indication of resection, marsupialization, or enucleation with or without Carnoy-solution is a clinical decision. Conclusion: Despite 100% penetrance, intrafamilial expression of the clinical phenomenon is variable. In child morbidity, the parents’ lifelong co-screening should be mandatory by radiological and clinical investigation. Late-onset KCOT should be resected en-bloc, including soft tissue movement. Enucleation has less morbidity for mandibular keratocysts near the nerve. Carnoy-solution helps minimize the risk of relapse.