A clinicoradiological study of odontogenic carcinomas and their impact on clinical diagnosis

To investigate the clinical and radiological characteristics of odontogenic carcinomas (OCs) and evaluate their impact on early clinical diagnosis.

The clinical and radiological features of all patients with OCs in our pathology record from January 1988 to December 2009 were retrospectively reviewed. The impact on a tentative diagnosis before final histological examination of clinical, panoramic and CT features was investigated.

Of 474 cases with malignant jaw tumours, 417 (88%) were gingival squamous cell carcinomas (SCCs) and 27 (6%) were OCs. The average age of the patients with OCs was significantly lower than that of those with gingival SCCs. 20 OCs were in the mandible and 7 were in the maxilla. 22 OC patients (81%) had pain and/or swelling as an initial symptom of the disease. Although the majority of OCs showed irregularly contoured radiolucency, one-third of the cases showed cyst-like radiolucency totally or partially surrounded by a sclerotic rim on panoramic radiography. Permeative or gross cortical bone destruction and mass extension outside the jaw bone were found on CT and a diagnosis of malignant tumour was more common. Mass extension outside the cortex had a significant influence on malignant diagnosis. However, 22% of the patients were still clinically diagnosed as having osteomyelitis after CT.

Although CT was useful to obtain a diagnosis of malignant tumour in OC patients, 22% of patients were clinically diagnosed as having osteomyelitis even after CT. When an osteomyelitis case is resistant to conventional therapy and gross bone destruction and/or mass extension is found on CT, a histopathological examination should be done.