AB291. SOH26AB_0438. Case report of malignant transformation of an odontogenic lesion in a special needs patient/intellectual disability—the importance of clinical surveillance

Background: Malignant transformation of odontogenic lesions is an important clinical entity that can be challenging to diagnose and manage. There is a need for more case descriptions to guide these challenges. We address this deficit in the following.

Case Description: This case report presents an interesting case of malignant transformation of an odontogenic cyst into a squamous cell carcinoma (SCC), highlighting the importance of clinical surveillance. A 34-year-old male attended the Oral and Maxillofacial Department with a mass on the left maxilla, which was subsequently diagnosed as SCC. Ten years prior, he presented with pain in the left maxilla. Orthopantomogram (OPG) at the time revealed a radiolucent lesion on the left posterior maxilla associated with an impacted ectopic premolar tooth. The clinical diagnosis was an odontogenic cyst. His medical history was significant for Lujan-Fryn’s syndrome, epilepsy, attention-deficit/hyperactivity disorder (ADHD), and moderate intellectual disability. Given the patient’s complex medical and social history, a clinical decision was made to monitor him. However, he was lost to follow-up after 2 years. Examination today revealed an ulcerated exophytic mass on the left posterior maxilla, and Incisional biopsy confirmed invasive moderately differentiated SCC. Following radiological investigations, the case was discussed at the head and neck multidisciplinary team (MDT), where minimally invasive surgical treatment was recommended. As such, he underwent left partial maxillectomy with preservation of the floor of the nose, left neck dissection, and was fitted with a maxillary healing plate. The patient also received post-operative radiotherapy.

Conclusions: Oral SCC continues to be a severe and incapacitating disease. Since odontogenic cysts are considered oral potentially malignant disorders, clinical monitoring of the cyst was a feasible treatment option given the difficulty in managing a patient with moderate intellectual disability. This case, however, presents a rare instance of malignant transformation, highlighting the importance of vigilant surveillance of oral lesions.

Keywords: Clinical surveillance; malignant transformation; odontogenic cyst; oral squamous cell carcinoma (oral SCC); case report