Aggressive fibrous dysplasia of the maxillary sinus

Abstract

Fibrous dysplasia is usually a slowly progressive, benign disease that develops over several years and presents with deformity or mild symptomatology. Five of 34 patients (ages 4-21 years), who were subsequently diagnosed histologically as having fibrous dysplasia of the maxillary sinus, rapidly developed soft tissue masses of the malar region over a period of less than 4 months with accompanying pain (2 patients) and nasal obstruction and exophthalmos (2 patients). Each was clinically suspected of having a sarcoma; two had been thought to have an "osteofibrosarcoma" on initial biopsy at outside hospitals. After resection, all lesions developed regrowth. At histopathologic examination, both initial and recurrent masses proved to be typical fibrous dysplasia with spicules of woven bone in cellular, sometimes vascular, fibrous tissue. No malignant degeneration was found. On conventional radiography, aggressive fibrous dysplasia produced opacification and expansion of the maxillary sinus and apparent disruption of its wall with an associated soft tissue mass. Computed tomography (CT) demonstrated voluminous heterogeneous masses with "ground glass appearance", calcifications, areas of enhancement, low attenuation, cystic areas, and a thinned, sometimes interrupted, maxillary wall. Despite the aggressive clinical course for both initial and recurrent lesions, the CT findings of a "ground glass" mass with calcifications surrounded by a maxillary sinus wall, even if incomplete, can suggest the diagnosis of aggressive fibrous dysplasia.

Locally Aggressive Fibrous Dysplasia Mimicking Malignancy: A Report of Four Cases and Review of the Literature

“…The incidence of locally aggressive fibrous dysplasia is not known. Numerous of the previously published reports of locally aggressive fibrous dysplasia described occurrence in the craniofacial skeleton, especially the maxilla and mandible in young patients [4,5,8,10,12,14,17]. Outside this location, locally aggressive fibrous dysplasia has been reported in the proximal and distal humerus, rib, pelvis, distal femur, and proximal tibia (Table 1), mostly in skeletally mature patients.…”

“…For patients with fibrous dysplasia, sudden appearance of pain or swelling is highly suggestive of pathologic fracture or malignant transformation. Locally aggressive fibrous dysplasia also has been associated with deformity or chronic pressure symptoms in the craniofacial region [14,17].…”

“…The MR images may show cortical destruction but MRI is the most sensitive in detecting the soft tissue extension. Unlike conventional MRI, gadolinium-enhanced dynamic subtraction MRI may be helpful in differentiating malignant tumors from benign and inflammatory lesions [17]. Overall, the MRI features are nonspecific and cannot differentiate malignancy from locally aggressive fibrous dysplasia.…”

“…CT is superior to MRI in evaluating endosteal scalloping, matrix calcification, cortical thinning, presence of a cortical shell, and cortical destruction. The gadolinium-enhanced subtraction MRI and CT may be helpful in surgical planning and for followup [17].…”

“…The clinical course of locally aggressive fibrous dysplasia is unpredictable. Some lesions may become stable with or without medical treatment whereas others may progress despite medical therapy [17]. Schofield [14] reported local recurrence after surgical treatment of a patient with locally aggressive fibrous dysplasia but distant metastasis or malignant transformation of locally aggressive fibrous dysplasia has not been reported.…”