# Malignant Recurrence of Benign Odontogenic Tumors (A Single Center Cross-Sectional Study)

## TL;DR

This study examines the rare occurrence of benign odontogenic tumors turning malignant, highlighting the importance of monitoring and treatment.

## Contribution

The study documents the unusual recurrence of benign odontogenic tumors as malignancies in a single center.

## Key findings

- Out of 357 odontogenic tumors, 21 were malignant with 3 cases arising from previously benign tumors.
- Recurrent malignancies were diagnosed in the maxilla as ghost cell odontogenic carcinoma and primary intraosseous carcinoma.
- A slight male predilection and higher incidence in middle and old age groups were observed.

## Abstract

Despite their rarity, malignant odontogenic tumors (MOT) represent an important group of oral lesions characterized by their variable clinical presentations and sometimes unexpected biological behavior.

The purpose of this retrospective cross-sectional study was to evaluate the number, types, and frequency of MOT and to investigate the relative rate of malignant transformation in recurrent odontogenic tumors (OT).

The records of patients diagnosed with OT in the hospital of the Faculty of Dentistry, Cairo University, were reviewed over 10 years (2013-2022). The OT were investigated for frequency, age, gender, site, and recurrence. The data were recorded and then analyzed using SPSS software version 25.

Among 5543 oral excisions, 357 cases of them were OT, including 336 benign (94.1%) and 21 malignant neoplasms (5.9%). Among the odontogenic malignancies, 18 lesions (85.7%) appeared de novo, and 3 lesions (14.3%) developed as recurrent of previously classified benign tumors. A high incidence was observed in the middle and old age groups (90.4%) with a median age being 42. Slight male predilection (1.3:1) was noticed. The mandible was the highly affected site but all recurrent cases were diagnosed in the maxilla as ghost cell odontogenic carcinoma (n = 2, 66.6%) and primary intraosseous carcinoma (n = 1, 33.3%).

Retrospective analysis of the relative frequency of MOT and the documentation of the unusual recurrence of benign OT as a malignancy enhances our understanding of OT behavior and the need for appropriate therapy and clinical follow-up.