Transformation of an odontogenic keratocyst into a solid variant of odontogenic keratocyst/keratoameloblastoma during long‑term follow‑up: A case report

Abstract

Keratoameloblastoma (KA) and solid variant of odontogenic keratocyst (SOKC) are rare odontogenic lesions, and their relationship and differences are unclear. The present study described a case that started as an odontogenic keratocyst (OKC) and transformed to SOKC/KA upon recurrence. Briefly, a 26-year-old man presented with swelling in the right cheek and was referred to the Department of Oral and Maxillofacial surgery, Hiroshima University Hospital (Hiroshima, Japan). At the initial visit, unicystic bone permeation was observed extending from the right canine to the molar, maxillary sinus and nasal cavity. After the biopsy, the patient underwent excisional surgery and was diagnosed with OKC. Thereafter, the lesion recurred six times over a period of 13 years and showed different histopathological features from those of the primary lesion, all consisting of numerous cysts with keratinization, which were diagnosed as SOKC/KA. The Ki-67 positivity rate was ~10%, which was higher than that of the primary lesion, but there was no atypia. Genetic analysis of the recurrent lesion revealed mutations in adenomatous polyposis coli and Kirsten rat sarcoma viral oncogene homolog. This case originated from OKC, and the morphological features of OKC and KA were mixed upon recurrence, supporting the commonality and association between the two. However, multiple mutations different from those of OKC and ameloblastoma were detected, suggesting an association of SOKC/KA with increased proliferative activity and a high recurrence rate.

Immunohistochemical Analysis of Dentigerous Cysts and Odontogenic Keratocysts Associated with Impacted Third Molars—A Systematic Review

“…GPC3 is more sensitive in determining the aggressiveness among aggressive odontogenic tumors. Yamasaki et al (2024) [ 120 ] To describe the transformation of an odontogenic keratocyst (OKC) into a solid variant of odontogenic keratocyst/keratoameloblastoma (SOKC/KA) during long-term follow-up and analyze genetic mutations. Study Type: Case report and genetic analysis.…”

Clinical and radiological documentation of complete remodeling of the mandibular bone after the enucleation of a large odontogenic keratocyst: 15 years follow-up of a unique case - A case report

“…The most extended follow-ups regarding the treatment of OKC described in the literature are 12 and 13 years [ 21 , 22 ]. In this case report, the clinical and radiological documentation over 15 years showed mandibular bone remodeling after enucleation of a well-defined multilocular OKC in the 35–45 region with perforation in the cortical region treated.…”