"Hybrid" lesion of the maxilla

Abstract

Juvenile ossifying fibroma is an uncommon benign but aggressive fibroosseous lesion that affects the craniofacial skeleton. Their distinct clinical and histopathological features warrant the lesion to be considered as a separate entity from other fibro-osseous group of lesions such as fibrous dysplasia and cemento ossifying fibroma. Concomitant development of secondary aneurysmal bone cyst may rarely occur, which makes the lesion more aggressive and difficult to treat. We report a case of a 6 year old girl who was diagnosed with aneurysmal bone cyst during her earlier presentation at a private hospital and was treated for the same. The lesion recurred within 6 months. The second incisional biopsy specimen revealed features of trabecular variant of juvenile ossifying fibroma along with areas of aneurysmal bone cyst.

Keywords: Hybrid lesion; aneurysmal bone cyst; juvenile ossifying fibroma; trabecular variant.

Figure 1

Diffuse swelling over the left middle third of face

Figure 2

Intraoral swelling seen on the palate

Figure 3

OPG showing diffuse radiopacity in the left maxillary sinus region

Figure 4

Axial CT showing lesion in the left maxillary sinus with nasal septum deviation

Figure 5

Coronal CT revealing superior displacement of the left orbital floor

Figure 6

Immature bony trabeculae with peripheral osteoid (arrow) and adjacent area of hemorrhage (H) (H and E, 200×)

Figure 7

Section showing blood filled cavity (H and E, 200×)

Figure 8

Section showing multinucleated giant cells (arrow) close to extravasated red blood cells (C) (H and E, 400×)