An interesting case report of ossifying fibroma of maxilla
Complaints:
17 years old female patient came with c/o
1. Swelling right side of cheek - 3 years
2. Progressive increase in size +
3. Pain and tenderness ++
4. Loosening of upper teeth on right side ++
Clinical features:
Swelling right side of cheek +
Firm in nature
Occupying the right maxilla
Right nasolabial fold obliterated
Mass obliterates bucco gingival sulcus
Loosening of right upper teeth except the last molar
Clinical photograph of the patient showing cheek swelling
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Clinical photograph of the patient lateral view
Photograph showing palatal swelling
Imaging:
CT scan of nose and paranasal sinuses showed soft tissue shadow in the right maxillary sinus with erosion of its anterolateral, medial and inferior walls. Hard palate was found to be eroded.
With the clinical diagnosis of ossifying fibroma patient was taken up for surgery.
A partial maxillectomy was done through caldwell luc incision.
Biopsy report came up as ossifying fibroma.
Discussion:
This is a rare fibroosseous neoplasm arising from cranial bones. Usually affects individuals in their teens. This lesion is usually non encapsulated but well demarcated from surrounding normal bone. Histologically bone is replaced by fibrous stroma which is cell rich containing osteoid material without osteoblasts. This tumor is usually asymptomatic but when aggressive can cause:
1. Cosmetic defects
2. Involvement of orbit
3. Involvement of adjacent vital structures like skull base
History:
It was Menzel who described these lesions in 1872.
Ossifying fibromas share many pathological features with that of fibrous dysplasia. In order to differentiate between these two lesions radiologic criteria was introduced. Ossifying fibromas in CT scans are seen as expansile lesions with clear cut demarcation between normal bone and dysplastic bone. Usually non ossified fibrous elements predominate in ossifying fibromas in contrast to thickened bone seen in fibrous dysplasia. However discrete areas of calcification can be seen.
Histopathological distinction between ossifying fibroma and fibrous dysplasia:
1. Lesional circumscription - reliable indicator for ossifying fibroma This is due to the fact that ossifying fibroma being a benign neoplasm is well demarcated from surrounding normal osseous tissue, where as fibrous dysplasia is a developmental anamoly and it merges imperceptibly with the surrounding normal osseous tissue.
2. Variability of tissue composition - In ossifying fibroma tissue composition changes from field to field. This includes bone to fibrous tissue ratio, admixture of woven and lamellar bone, and degree of mineralization. In fibrous dysplasia the bone to fibrous tissue ratio is rather uniform.
3. Natural history of growth of ossifying fibroma is one of continuous growth a feature of benign neoplasm where as fibrous dysplasia stops growing when the skeleton matures and bone ossifies.