Fibrous Dysplasia: Clinicopathologic Presentation of 36 Cases

Objective: Fibrous dysplasia is a slowly progressing bone lesion resulting from displacement of the normal medullary bone with abnormal fibroosseous tissue. The aim of this study was to assess the similarities and differences of our cases in relation to published reports. Material and Method: In this study, the archives of the Uludag University Medical Faculty Department of Pathology were screened for fibrous dysplasia cases between 2004 and 2016. Results: Within the mentioned period, there were 36 cases diagnosed as fibrous dysplasia. There were 21 male, and 15 female cases with an average age of 27.8±14.8 years (range 7-79 years). The most frequently affected sites were femur, costae, and craniofacial bones. There was one case localized to metacarpal bone, a very rare affection site. There were 4 polyostotic cases including 2 cases of McCune-Albright syndrome. Pelvic bone was affected in the polyostotic type, similar to published reports. Unlike former reports, however, long tubular bones were affected in male patients in our series. In our series, 32 cases had classical fibrous dysplasia, 3 cases had fibrocartilaginous, and one case had fibroosseous variants. Four cases localized to costae were accompanied by aneurysmal bone cyst. The presenting symptom was pathological fractures in a total of 4 cases, 3 localized to the femur, and 1 to the costa. Recurrence occurred in 5 cases treated with curettage. Two of the monostotic fibrous dysplasia cases developed malignant transformation into osteosarcoma. Conclusion: We conclude that our series of fibrous dysplasia cases have slight differences and mainly similar characteristics with the series reported earlier, when all features are taken into consideration

Enhancer of zeste homologue 2 (EZH2) expression in synovial sarcomas as a promising indicator of prognosis

Synovial sarcoma (SS) is a type of soft-tissue sarcoma, often linked to poor survival. Although overexpression of enhancer of zeste homologue 2 (EZH2) has been associated with poor prognosis in different tumors, a few studies investigated this link in SS. Here, we analyzed the relationship between EZH2 expression and prognostic factors in SS. We included 29 patients with SS. Immunostaining of EZH2 was performed with (D2C9) XPTM Rabbit mAb antibody, and the results were classified as low EZH2 expression (negative or weak expression) and high EZH2 expression category (moderate or strong expression). Analysis of survival in relation to prognostic factors was performed with Kaplan-Meier survival curves and Cox proportional hazard regression analysis. Our sample included 19/29 female and 10/29 male patients, with age range 16-63 years. The tumor diameter ranged from 2 to 15 cm. Necrosis was observed in 15/29 cases. Sixteen cases had >10 mitoses per 50 high-power fields (HPFs). Out of 29 cases, 14 showed low and 15 had high EZH2 expression. Statistically significant results were obtained for the association between the presence of metastasis and necrosis (p = 0.042), high EZH2 expression and distant metastasis (p = 0.018), high EZH2 expression and necrosis (p = 0.016), and high EZH2 expression and the tumor size >5 cm versus tumor size ≤5 cm (p = 0.014). Patients with all of the following: the tumor size ≤5 cm, low EZH2 expression, and without necrosis and distant metastasis had significantly longer survival time. Our results are consistent with previous studies, suggesting that EZH2 overexpression is an indicator of poor prognosis in SS