BACKGROUND Monostotic fibrous dysplasia is a benign proliferation of fibrous and osseous tissues that expand medullary bone to cause symptoms due to compression of adjacent organs and anatomical structures. Focal seizures are rarely the first sign of this kind of lesion. This report describes a young female patient with left-sided focal motor seizures associated with fibrous dysplasia presenting as a mass in the right parietal bone. CASE REPORT An 18-year-old female student with left-sided focal motor seizures presented with a mass in the right parietal bone. Computed tomography revealed an expansile mixed-density lesion on the right parietal bone, a relatively homogeneous ground-glass appearance in the outer circumferential portion, and a lucent eccentric area with thinned but sclerotic borders. Magnetic resonance imaging revealed a homogeneously hypointense signal on T1WI, a small hyperintense signal on T2WI, and avid enhancement signal intensity on post-contrast T1. Electroencephalogram showed inter-ictal epileptiform activities derived from the right fronto-central lobe. Surgical en bloc resection with a margin of normal bone and cranioplasty were performed. Histopathology showed features indicative of fibrous dysplasia, including osteoid trabeculae arranged haphazardly in a dense fibroblastic stroma, irregular trabeculae lacking conspicuous osteoblastic rimming, and intervening fibrous stroma containing cytologically bland spindle cells. The patient achieved seizure control and has remained neurologically intact. CONCLUSIONS This report has highlighted the importance of early diagnosis of fibrous dysplasia of bone to exclude primary bone malignancy or bone metastasis, to ensure rapid management and symptom control.

BACKGROUND: Fibrous dysplasia is a disorder in which normal bone is gradually replaced by immature fibro-osseous tissue, with an incidence of less than 7% of all benign bone tumors. The management of this disease is a challenge for plastic surgeons and neurosurgeons.
OBJECTIVE: To describe the diagnostic, therapeutic, and outcome approach of patients with craniofacial fibrous dysplasia seen at the Plastic Surgery Service of the Hospital San José in Bogotá, Colombia.
METHODS: This is a descriptive and retrospective case series study of patients diagnosed with monostotic and polyostotic fibrous dysplasia treated at the Plastic Surgery Department of Hospital San José during the period from January 1, 2010, to July 31, 2023.
RESULTS: All (n=10) of the patients had monostotic craniofacial fibrous dysplasia. The most affected bones in patients with monostotic fibrous dysplasia were zone I bones (n=10, 100%), followed by zone II bones (n=2, 20%). Patients with zone I and II involvement manifested throbbing headaches associated with phosphenes and tinnitus (n=8, 80%) and pain during occlusion associated with edema in the affected cheek (n=5, 50%). Physical examination showed that patients with orbital wall involvement (zone I bone) had ocular dystopia (n=7, 70%).Regarding the treatment received by the patients, 90% (n=9) of the patients received surgical management as primary treatment, with orbitotomy, replacement, and/or remodeling of the roof and lateral wall of the orbit with bone graft, drilling, canthoplasty, ciliary suspension being the most frequently performed procedure (n=6, 60%). Of the patients, 20% (n=2) required reintervention.
CONCLUSIONS: FD is a slowly progressive benign fibro-osseous disease that requires a timely, individualized, and multidisciplinary diagnosis and treatment to obtain favorable clinical and surgical results.The mainstay of treatment is surgery as a preventive measure since it is important to avoid future functional alterations that, depending on the location of the dysplasia, would cause a high risk of alteration of adjacent structures.

Fibrous dysplasia (FD) is a rare skeletal disorder characterized by abnormal fibro-osseous connective tissue replacing normal bone. Despite its benign behavior, craniofacial FD can cause morphological disfigurement, headache, and even blindness as a result of the produced mass effect. Surgical resection is recommended when the patient shows apparent clinical symptoms or aggravating facial asymmetry. Postoperative complications have been reported, such as hematoma, surgical site infection, abscess formation, resorption of the bone graft used for reconstruction, and recurrence. An aneurysmal bone cyst (ABC) is a rare benign bony lesion that can occur secondary to preexisting bone tumor. Secondary ABCs in craniofacial FD are extremely rare in the literature, accounting for less than 30, all of which are either case reports or series. We report an extremely rare case of symptomatic secondary ABC arising from craniofacial FD that had been misdiagnosed with abscess formation or recurrence and was surgically removed. Notably, 17 years elapsed between the primary surgery and the complication of secondary ABC. The patient underwent total removal of secondary ABC. After surgery, symptoms were relieved, with no recurrence observed during a 6-month follow-up.

Fibrous dysplasia is an uncommon genetic disorder in which bone is replaced by immature bone and fibrous tissue, manifesting as slowgrowing lesions. Sporadic post-zygotic activating mutations in GNAS gene result in dysregulated GαS-protein signaling and elevation of cyclic adenosine monophosphate in affected tissues. This condition has a broad clinical spectrum, ranging from insignificant solitary lesions to severe disease. The craniofacial area is the most common site of fibrous dysplasia, and nine out of 10 patients with fibrous dysplasia affecting the craniofacial bones present before the age of 5. Surgery is the mainstay of treatment, but the technique varies according to the location and severity of the lesion and associated symptoms. The timing and indications of surgery should be carefully chosen with multidisciplinary consultations and a patient-specific approach.

A systematic review was undertaken to examine the spontaneous of craniofacial fibrous dysplasia (FD) into osteosarcoma (OS).
Five databases were searched, and data were evaluated in 2 subsets: (1) frequency analysis involving only cross-sectional studies that specifically examined patients for osteosarcomatous transformation, thereby allowing a calculation of the frequency of transformation of craniofacial FD, and (2) case analysis of case reports and case series of FD that underwent osteosarcomatous transformation. Quality assessment of the studies in the frequency and case analyses was performed.
Seven cross-sectional studies involving 779 patients in the frequency analysis documented transformation of craniofacial FD into OS in 13 patients, for a frequency of 1.67%. Of the 18 separate cases of osteosarcomatous transformation in the case analysis, 11 (61.1%) occurred in females, 11 (61.1%) developed from monostotic FD, and 7 (38.9%) arose in the mandible, with 5 in the maxilla (27.8%) and 6 (33.3%) in other craniofacial sites. The mean age of the patients at the time of malignant diagnosis was 36.4 years, with an average of 11.3 years from FD diagnosis to the appearance of OS. The quality of the articles ranged from fair to excellent.
The risk of osteosarcomatous transformation of craniofacial FD is low, but the possibility of transformation should be taken into consideration by clinicians, as this will guide treatment and follow-up regimens.

The majority of bone angiosarcomas are primary tumors while secondary angiosarcomas arise after radiation therapy or bone infarctus. This article presents a case of malignant transformation of monostotic fibrous dysplasia into angiosarcoma. An 80-year-old female presented with pain on right cruris. Radiological examination revealed a lesion with lytic areas and destruction of cortical bone on right tibia. Gross and histopathological examination showed two areas with an abrupt transition. The solid component was composed of curved, immature bony trabeculae in a fibroblastic stroma. The other component involved epitheloid cells forming slit-like vascular spaces. The diagnosis of angiosarcoma and fibrous dysplasia was given. Malignant transformation of fibrous dysplasia into angiosarcoma is extremely rare; as this is the sixth case in the existing literature. Prognosis of fibrous dysplasia is generally good and less than 1% of the patients develop a malignant tumor. Therefore, patients with fibrous dysplasia should be offered a life-long follow-up.

OBJECTIVE. The purpose of this study was to explore the temporal changes in fibrous dysplasia (FD) at radiographic follow-up. MATERIALS AND METHODS. A total of 138 patients with FD who had undergone extremity radiography at least twice with a minimum 12-month interval between examinations were enrolled in this study. FD was monostotic in 99 patients and polyostotic in 39 patients. Patients were also classified according to skeletal maturity as follows: Patients 16 years old or younger were classified in the skeletally immature group (n = 34), and patients 17 years old or older were classified in the skeletally mature group (n = 104). We compared the initial and follow-up radiographs for the following findings: lesion size, opacity, sclerotic rim, calcification, and trabeculation. RESULTS. Of the 138 patients, radiographic follow-up showed no change in lesion size in 101 patients (73.2%), progression in 31 (22.5%), and regression in six (4.3%). FD in immature bones progressed more often than FD in mature bones (23/34 [67.6%] vs 8/104 [7.7%], respectively; p = 0.000), and polyostotic FD had a greater chance of regressing than monostotic FD (4/39 [10.3%] vs 2/99 [2.0%]; p = 0.032). A temporal change in FD lesion opacity was noticed in a minority of patients (19/138, 13.8%). Variable changes were observed in the sclerotic rim, calcification, and trabeculation. CONCLUSION. The radiographic follow-up of FD showed that approximately a quarter of lesions changed in size over time. Regardless of the change in lesion size, opacity and several morphologic features of FD changed during the follow-up period, which might reflect the histopathologic evolution of FD.

暂无摘要。

Monostotic fibrous dysplasia (MFD) of the lumbar spine represents an exceedingly rare lesion. A 26-year-old patient presented with a progressive osteolytic lesion of the vertebral body L2 and the diagnosis of MFD. A minimally invasive left-sided eXtreme Lateral Interbody Fusion (XLIF) approach with resection of the vertebral body L2 with placement of a mesh cage was performed. No complications were observed perioperatively and the symptoms rapidly improved. Minimally invasive piecemeal resection with a combined dorsolateral approach showed a favorable clinical and radiological outcome and seems to be a safe and reliable technique for MFD.

Monostotic fibrous dysplasia is a rare osteodystrophy that typically affects adolescents, manifests later in life, and may be associated with subclinical hormonal imbalances. It can lead to serious complications, including visual compromise. We report a case of presumed monostotic sphenoid fibrous dysplasia presenting with transient abducens nerve palsy and esotropia in an otherwise healthy infant. The mechanism of transient, noncompressive abducens nerve palsy is not clearly understood but has been theorized to be secondary to localized inflammation during a cycle of florid bone remodeling that includes cyst formation, microhemorrhage, and resorption.