Objective: To investigate the clinicopathological and radiological features of benign fibro-osseous lesion (BFOL). Methods: Sixty-five cases of craniofacial BFOL, eight cases of peripheral ossifying fibroma (POF) and one case of low-grade central osteosarcoma diagnosed at Sichuan Provincial People's Hospital between January 2010 and March 2019 were collected. The clinicopathologic features, hematoxylin-eosin and immunohistochemical (IHC) staining and radiographic features were analyzed. MDM2 gene amplification was detected by FISH in difficult borderline cases. Results: This cohort of BFOLs included 50 cases of fibrous dysplasia (FD), 12 cases of ossifying fibroma (OF), and three cases of juvenile psammomatoid ossifying fibroma (JPOF). The average ages of patients with FD,OF and JPOF were 31.7, 39.2 and 26.0 years respectively. The male to female ratio was 1.0∶1.8.The average age of POF was 47.0 years, with male to female ratio of 1∶7. Patient of low-grade central osteosarcoma was a 48-year-old man. Twenty-seven cases of FD were located in the jaw, and 23 cases were in other craniofacial bones. Nine cases of OF were located in the jaw, and three cases were in the nasal cavity. Two cases of JPOF were in the nasal sinus, and one was in the jaw. All POF were located in the gingiva, and low-grade central osteosarcoma was located in the mandible. The imaging features of FD were luffa-like or ground-glass like signal shadows with poorly defined borders with expansion. OF had clear borders or sclerosing margins. Both JOF and low-grade central osteosarcoma were expansile intraosseously and with focally invasive nodular masses with ground-glass like signal shadows; and POF showed soft tissue mass with bone formation. Histological features of BFOLs showed mixed fibrous and irregular osteoid lesions. FD had no clear relationship with the host bone and no osteoblasts surrounded the bone trabeculae. Osteoblasts rimming was found in OF, and the boundaries of the host bone were clear. JPOF and low-grade central osteosarcoma infiltrated the host bone focally, and the latter showed mild cellular atypia. MDM2 amplification was detected in low-grade central osteosarcoma. Conclusions: BFOLs are a group of fibro-osseous lesions with similar morphology in the head and neck and face, but their clinical features and prognosis are different; and their imaging and histological characteristics are also slightly different. Attentions should be given to the combination of clinical, imaging and pathologic features of BFOLs, especially the differential diagnosis between BFOLs and low-grade central osteosarcoma. Molecular detection could be used to assist the diagnosis in difficult cases.
目的： 探讨颅面部良性纤维-骨性病变（benign fibro-osseous lesions, BFOL）的临床、影像学、病理学特征及与其他颅面部相似骨性病变的异同。 方法： 收集四川省人民医院2010年1月至2019年3月的65例颅面部BFOL、8例外周性骨化性纤维瘤（ossifying fibroma,OF）及1例低级别中央型骨肉瘤的病例资料及存档切片。所有病例采用HE及免疫组织化学染色，5例疑难交界性病例采用荧光原位杂交（FISH）检测MDM2基因扩增。 结果： 65例BFOL中包括50例纤维结构不良（fibrous dysplasia，FD），12例OF，3例幼年性OF（均为幼年性沙砾体样OF亚型）。患者平均年龄FD为31.7岁，OF为39.2岁；幼年性OF为26.0岁；BFOL病例男女比为1.0∶1.8。外周性OF患者平均年龄47.0岁，男女比为1∶7；FD样低级别中央型骨肉瘤为48岁男性。发病部位FD为颌骨27例、颅面骨23例；经典型OF为颌骨9例、鼻腔3例；幼年性沙砾体样OF为鼻腔鼻窦2例、颌骨1例；外周性OF均发生于牙龈；低级别中央型骨肉瘤为下颌骨肿块。影像学特征FD为边界不清、轻度膨胀的骨内丝瓜瓤样或毛玻璃样密度影；OF为边界清楚的毛玻璃样肿块；幼年性OF及低级别中央型骨肉瘤均为骨内膨胀性生长且局灶浸润性边界的结节状肿块。组织学特征：BFOL镜下均为纤维及不规则骨性混合增生性病变，其中FD与宿主骨相互移行，骨小梁周围无骨母细胞围绕；OF骨小梁周围可见骨母细胞环绕，与宿主骨界清，FD及OF均可见牙骨质样形态。幼年性沙砾体样OF及低级别中央型骨肉瘤局部推挤式累及宿主骨，前者细胞密度高，后者见细胞不典型性。外周性OF为骨外病变。FISH检测结果显示低级别中央型骨肉瘤存在MDM2基因扩增。 结论： BFOL为颅面部一组形态学相似的纤维-骨性增殖性病变，其各自的临床特征及预后不同，影像学改变及组织学特点也有细微差异。BFOL需要特别注意与低级别骨肉瘤的鉴别诊断，疑难病例可分子检测辅助诊断。.
Keywords: Diagnosis, differential; Facial neoplasms; Fibroma, ossifying; Fibrous dysplasia of bone; In situ hybridization, fluorescence.