目录
Extracted from Craniofacial and Maxillofacial Surgery in Children and Young Adults, Volume 2
GIANT CELL LESIONS
The most benign jaw tumors in childhood.
It is increasingly recognized that the innocuous reputation established for this tumor in the early literature does not always apply, but at present no histologic markers of tumor behavior are available to assist clinicians in deciding on treatment.
It is may be called a giant cell reparative granuloma, giant cell granuloma, giant cell tumor of the jaw, and pseudo-giant cell tumor. These central bony tumors should not be confused with the soft tissue peripheral giant cell lesion or giant cell epulis, which is histologically similar, but considered to constitute a different clinical entity.
Typically occurs in adults between 20 and 25 years of age.
The most common presenting symptom is a bony swelling, sometimes with associated pain and loosening or devitalization of teeth. Maxillary tumors may cause nasal obstruction or recurrent nosebleeds. Most tumors occur in the anterior jaw, and are more common in the mandible than the maxilla.
There are no pathognomonic radiologic features. The typical appearance is a radiolucent lesion with welldefined margins and an overlying wispy opacification that may represent intralesional calcification. The lesion is unilocular, but may have scalloped margins. There is bony expansion with cortical thinning, and perforation through the bone may occur. Teeth in contact with the lesion usually do not show evidence of external root resorption, but may lose the lamina dura. On computed tomography (CT) scan, larger tumors may be ill-defined, expanding into the sinus cavities or the nasal vault, and causing ballooning out of bony walls with destruction. Macroscopically, the lesion is composed of reddish, hemorrhagic, spongy tissue that may have a gritty consistency. Microscopic examination shows a loose, vascular stroma containing spindle-shaped fibroblastic cells, multinucleated giant cells, collagen, small areas of hemorrhage, and osteoid or new bone formation.
In general, the lesion can be distinguished histologically from other bone tumors that contain giant cells, including fibrous dysplasia, aneurysmal bone cyst, and ossifying fibroma. In particular, all patients must undergo appropriate investigation for hyperparathyroidism, especially in the presence of multifocal or recurrent giant cell jaw lesions.
It is evident that curettage, the historically recommended treatment for these lesions and their recurrences, will be inadequate in a significant number of patients.
In the absence of histologic markers, clinical features alone must form the basis of treatment decisions. A lesion that is large at the time of initial diagnosis and associated with extensive bony destruction (especially if it occurs in a young person) requires excisional surgery rather than simply curettage. Decisions about appropriate treatment of recurrent lesions must take into account the adequacy of the initial treatment, rate of growth, and speed of recurrence. When definitive excisional surgery is indicated, the ability to provide functional and aesthetic reconstruction and rehabilitation is essential. Radiotherapy has not been shown to be effective in treating giant cell jaw lesions. Furthermore, it would be inappropriate therapy for a benign lesion, especially in a child, because of the long-term interference with growth of the irradiated tissues and the potential for development of malignancy.
CONGENITAL (NEVOCELLULAR) NEVI
The management of a child with a congenital nevocellular nevus remains complex and con troversial. If the nevus is small and can be excised withprimary closure or is in an inconspicuous location, then the decision for removal based on malignant potential or for cosmetic reasons is straightforward. The difficulty arises when the removal of the congenital nevus will exact a (cosmetic or functional) cost that seems greater than the risk of conservative observation.
AGGRESSIVE FIBROMATOSIS
They represent a group of infiltrating fibrous proliferations that exhibit a biologic behavior intermediate between benign fibrous lesions and fibrosarcoma.
Aggressive fibromatosis is a nonencapsulated, nonmetastasizing fibrous tumor that has a tendency for local infiltration, persistence after min imal surgical procedures, and growth of the residual re currence after excision in up to 70% of patients.
The lesion is highly cellular and locally infiltrative and has a propensity to invade and erode bone, compromising vital structures within the head and neck.
Radiation therapy and chemotherapy can be used as adjuvant treatment if surgical margins are positive or if the tumor is believed to be unresectable.
Although fibromatosis may grow rapidly, it more fre quently presents as a painless, slow-growing firm swelling with ill-defined borders that begins as a fibroblastic proliferation which gradually infiltrates and invades the surrounding soft tissues and bone. Radiographically, the lesion may appear as a unilocular or multilocular radiolucency with borders that are usually well defined and may demonstrate external dental root resorption. Histologically, it is characterized by an abundance of well-differentiated spindle-shaped fibroblasts, which are separated by considerable collagen or reticular fibers.
Incompletely resected tumors are expected to remain persistent and demonstrate clinical recurrence over time and usually within the first 1 to 2 years.
Mackenzie has stated that the major errors in the man¬ agement of aggressive fibromatosis include the following:
- The surgeon who has accepted the apparent encapsulation of the tumor as an indication of innocence
- The pathologist who is lulled into a sense of false security by the cellular consistency of the tumor
- The probability that neither the surgeon nor the pathologist understands the natural history (clinical behavior) of the fibromatosis tumor.
Considering the tendency of these lesions to persist and grow, an aggressive initial surgical approach seems advisable whenever feasible.