Fibro-osseous lesions vs. central giant cell granuloma: A hybrid lesion
A 9-year-old boy was referred to our unit. He was complaining of swelling in the left mandibular angle region since 4 months. It was insidious in onset, slow growing, hard and not associated with pain. On extraoral examination the lesion was 4 × 3 cm2 and hard on palpation covered with normal skin. There was no history of pain or paresthesia and no previous history of trauma. Intraoral examination revealed a mild expansion of buccal cortical plate posterior to left permanent mandibular first molar with tenderness over lingual cortex distal to first permanent molar and mucosa covering the swelling was intact. The lower border continuity of mandible was maintained with a mild bulge in the lower border in the angle region. Mouth opening was 35 mm [].\nThe orthopantomograph revealed a well-defined unilocular radiolucency with scattered radiopacities with a bony sclerotic margin. The lesion extended anteroposteriorly from the distal root of mandibular deciduous second molar to 1.5 cm anterior to posterior border of mandible, superoinferiorly from superior border of mandible to 1 cm below the lower border of mandible with displacement of second permanent molar tooth bud toward the sigmoid notch [].\nOn aspiration of the lesion about 2 ml of blood mixed serous fluid was collected and sent for biochemical analysis. The biochemical analysis showed the protein content of fluid as 7.8 g/dl. An open biopsy was carried out under local anesthesia. After creating a small window through the thick covering bone on the buccal side of the lesion, a soft tissue specimen was taken out and sent for histopathologic examination.\nHistopathologic examination showed the presence of dense cellular fibrous connective tissue with numerous spindle-shaped fibroblasts. Focally numerous multinucleated giant cells and irregular trabeculae of osseous tissue rimmed by plump osteoblasts were evident. A Fine Needle Aspiration Cytology report of the fluid showed a protein content of 7.8 g/dl, and cytosmears revealed the presence of debris. Correlating cytologic and histopathologic features, it was reported as CGCG undergoing tumor degeneration leading to solitary bone cyst [].\nThe decision was made to go for the conservative surgical approach that is curettage of the lesion with the removal of displaced second permanent molar tooth bud. Since the lesion was extending along the ramus, it was found to be difficult to completely enucleate the lesion by the intraoral approach, hence, the decision was taken to go extraorally.\nThe lesion was approached through submandibular incision and the lesion was curetted []. The displaced tooth was removed. The inferior alveolar neurovascular bundle was not encountered during surgery since it was pushed downward. Perforation of the lingual cortex was observed at a higher level than the inferior alveolar canal, and lower border continuity was maintained. Postsurgical recovery of the patient was uneventful. The orthopantomograph taken on the first postoperative day shows the extent of surgical exploration [].\nThe excised specimen was sent for histopathologic examination which revealed the presence of connective tissue exhibiting highly cellular fibrous tissue with monotonous uniform plump fusiform fibroblasts interspersed with variable amounts of osteoid and woven bone predominantly arranged in irregular trabeculae. These bony trabeculae show plump osteocytes, rimmed by hyperchromatic basophilic osteoblasts. Some areas showed the presence of dark basophilic round to irregular calcified bodies. Separate foci of multinucleated giant cells were also found within the stroma. It was reported as JOF of the trabeculated type [].\nThe patient is on regular follow-up. The orthopantomographs at 3 months [], 6 months [], and 1 year [] interval show increased radio-opacity of the defect, and the expanded lower border is regaining its normal contour.