Conversion of Aneurysmal Bone Cyst into Fibrous Dysplasia: A Rare Pediatric Case Report

Abstract

Aneurysmal bone cyst (ABC) is an uncommon, non-neoplastic, expansive and erosive bone lesion. Considered as a pseudocyst due the lack of epithelial lining, the presence of giant cells and similarity to other lesions can make preoperative diagnosis difficult; biopsy findings must be co-related to complete clinical and radiological assessment. ABC's controversial etiopathogenesis and variable clinicopathological presentations have been widely described, but to date, there are just a few reports in literature describing the development of fibrous dysplasia (FD) from an ABC, and even less cases occurring in the jaws. We describe the case of an ABC in an 8 year-old male patient, affecting the body of the mandible, which showed accelerated growth associated to thinning of the buccal, lingual and lower cortical plates. The treatment consisted of repetitive surgical resection, curettage of the lesion and mandibular reinforcement with osteosynthesis reconstruction plates. A 16-month follow-up showed selflimitation of the overgrowth. The final histopathological and radiological analysis confirmed the FD diagnosis.

Atypical Presentation of Giant Mandibular Aneurysmal Bone Cyst with Cemento-Ossifying Fibroma Mimicking Sarcoma

“…Areas of osteoblastic differentiation with osteoid calcification can be seen. A third form also known as “mixed-type” contains solid and cystic areas [9]. The differential diagnosis includes telangiectatic osteosarcomas, cavernous hemangiomas, central giant cell granulomas (CGCGs), and brown tumors.…”

Custom Made Replacement of the Mandibular Condyle in a Case of Fibrous Dysplasia with Cystic Degeneration; A Case Report

“…An association between an ABC and fibrous dysplasia has been reported, wherein the exact relation remains unclear. One case report on an ABC of the mandibular condyle suggested conversion of an ABC into fibrous dysplasia, but acknowledged that the simultaneous presence of both conditions can also occur [ 14 ]. Another author, on the other hand, reported on cystic degeneration of cranial fibrous dysplasia causing rapid enlargement of the fibrous dysplastic lesion [ 15 ].…”