Aneurysmal bone cyst of the mandible: a rare case report and literature review

Abstract

Introduction and importance: Aneurysmal bone cysts (ABCs) are benign, non-neoplastic cystic lesions composed of multiple blood-filled cavities, which are separated by connective tissue septa and they constitute ~6 and 1.5% of all cases of the skull and jaws lesions, respectively.

Case presentation: Herein, the case of an 80-year-old male with a histologically confirmed diagnosis of ABC involving the body of the left mandible was presented. The patient underwent partial mandiblectomy after confirmation of the diagnosis using orthopantomography, a computed tomography scan, and a tissue biopsy. The patient was free from pain after 1-year of follow-up, and the control orthopantomography showed no evidence of recurrence. This was followed by reconstruction of the healed part of the bone with titanium plates and a piece of bone from the lateral two-thirds of the left femur and thereafter he was cosmetically well.

Clinical discussion: Patients with ABCs present with expansile and radiolucent bone lesions, which may be associated with displacement and loss of teeth due to alveolar bone erosion. Complete excision of the lesions is mandatory for the prevention of recurrence and increased morbidity.

Conclusion: ABCs that involve the jaws are extremely rare and are more likely to pose a diagnostic challenge as they are more likely to be confused clinically with other expansile radiolucent bone lesions such as ameloblastoma, osteoblastoma, and giant cell tumor among many others. Also, those with extensive bone matrix formation may sometimes be confused histologically with other bone forming tumors including osteosarcoma. Recurrence is common but it can be avoided or minimized by complete resection of the lesion.

Keywords: aneurysmal bone cyst; bone lesion; mandible.

Figure 1

Anteroposterior view of the orthopantomography showing a radiolucent lesion together with thinning of the cortical plates, expansion, and anterior displacement of the tooth number 34 (arrows).

Figure 2

Gross appearance of the excised mass together with a tooth. The mass consists of irregularly thin wall areas with bone spicules.

Figure 3

(A) Formation of cystic spaces filled with blood, (B) Proliferating multinucleated giant cells (arrow) (haematoxylin and eosins, ×200), (C) Focal area of fibrosis with cystic spaces without lining endothelial cells, and (D) Laying down of the bone matrix by the osteoblastic cells (arrows) (haematoxylin and eosins, ×200).