Spot Diagnosis

Ossifying fibroma

Ossifying fibromas were earlier classified with fibrous dysplasias as fibro-osseous tumors of the jaw. Now they are considered separate entities and actually a severe end of the spectrum of cemento-ossifying fibromas.

This young patient had an expansile lesion in the right maxilla, which showed remodelling of the sinus, with bone formation. This pattern is highly suggestive of a fibro-osseous lesion, not fibrous dysplasia and consistent with a diagnosis of an ossifying / cemento-ossifying fibroma.

Giant cell reparative granuloma

This 26-years old girl had a gradually increasing left cheek swelling. The CT showed an expansile lesion involving the left maxillary bone, effacing the sinus (Figs. 1-4). Marked thinning of the cortices was seen with heterogeneously enhancing soft tissue, without extra-osseous extension (Fig. 2). There was no osteoid or chondroid matrix. In the absence of signs of aggression, in the absence of an obvious "cystic lesion", this appearance is suggestive of, though not pathognomonic of a giant cell reparative granuloma.

GCRGs are proliferative fibroblastic lesions with multi-nucleated giant cells. It usually occurs in the 2nd decade in the jaw bones and is rare in the peripheral skeleton. It can be easily histologically differentiated from a typical giant cell tumor of the appendicular skeleton. This case is a typical example of a GCRG.

Calcifying Epithelial Odontogenic Tumor - Pindborg Tumor

This is a patient who had a gradually increasing right lower jaw mass. The OPG showed (Fig. 1) an expansile, osteolytic lesion with coarse trabeculae. The CT scan (Figs. 2, 3) showed an enhancing lesion with trabeculae with marked thinning of the buccal and lingual cortices. The 3DCT image (Fig. 4) showed the lesion in a 3D perspective.

Though the exact etiology is indeterminate, the appearances are suggestive of an odontogenic tumor and the differentials would include ameloblastoma and odontogenic myxoma. On biopsy, this turned out to be a calcifying epithelial odontogenic tumor, also called the Pindborg tumor.

This tumor is commonly seen around the age group of 40 and occurs in the pre-molar area of the manndible. It usually presents with poorly marginate borders and has mixed osteolytic and sclerotic areas.

Dental CT & Imaging

Each Thursday morning, will see a new jaw related case.

1. Ameloblastoma

2. Calcifying epithelial odontogenic tumor - Pindborg tumor

3. Adenomatoid odontogenic tumor

4. Odontogenic myxoma

5. Bone island

6. Osteoma mandible

7. Giant cell reparative granuloma

8. Brown tumors

9. Fibrous dysplasia

10. Ossifying fibroma

11. Polyostotic fibrous dysplasia

12. Dental cyst

Amelobastoma

This 32-years old man came with a right cheek swelling. The OPG showed an expansile, osteolytic lesion, involving the mandibular ramus (Fig. 1). A CT scan was performed, which showed an expansile, osteolytic lesion with enhancing soft tissue (Fig. 2), but without extra-cortical extension of the soft tissue. No lamellations were seen. The 3DCT (Fig. 3) showed the lesion well for pre-surgical evaluation.

Though odontogenic keratocyst and odontogenic myxoma are differentials, the absence of septae and lamellations argues for a diagnosis of an ameloblastoma, which was proved on biopsy.