Primary intraosseous carcinoma, NOS arising from a dentigerous cyst: A case report

Abstract

Introduction: Primary intraosseous carcinoma, NOS (PIOC), is a rare malignancy which has been described in the maxilla and mandible often arising from odontogenic cysts. The authors describe a case of PIOC arising from a dentigerous cyst associated with a lower right third molar in 78-year-old male. Aims: To demonstrate that seemingly innocuous pathology may represent a malignant process. In the presence of ‘red-flag’ symptoms, one must consider alternative diagnoses and action them accordingly. Findings and Discussion: The initial clinical and radiographic features suggested a common innocuous presentation, although other features which presented later were suggestive of malignancy. PIOC is treated conventionally by radical surgery to achieve a disease-free margin with adjuvant neck dissection. In the case described, the patient underwent hemi-mandibulectomy with neck dissection and fibula free flap reconstruction. Conclusion: Pathology associated with third molars is extremely common, very occasionally malignancy can mimic these more common conditions. As such, careful clinical examination of the affected site and neighbouring structures (including the lymph nodes of the head and neck) should be routinely performed in all patients. Even in the presence of typical features clinical and radiographic features, tissue samples should be sent for histopathological analysis of what may appear to be harmless follicular or early cystic tissue.