不典型部位软骨母细胞瘤

目的 探讨长骨骨骺和骨突以外不典型部位软骨母细胞瘤的临床、影像学和病理形态学特征,分析误诊原冈。方法 收集上海市5家大型综合性医院近12年内经病理证实的18例不典型部位软骨母细胞瘤的临床、X线和病理资料,作回顾性分析。肿瘤细胞的软骨分化倾向作S-100标记证实。结果18例中10例位于足部跗骨和小管状骨(55．6％),单骨发病最常见的是跟骨和距骨,平均发病年龄27．8岁,年龄＞25岁的成年人占55．6％。X线大多表现为膨胀性,多房性边界清楚的溶骨性骨质破坏。5例(28％)有局部骨皮质破坏,1例骨外软组织浸润,10例(55．6％)合并动脉瘤性骨囊肿或单纯性骨囊肿。术前临床无1例确诊,病理2例误诊,大多误诊为动脉瘤性骨囊肿或巨细胞瘤。结论 应综合考虑临床表现、X线特征以及病理形态改变进行不典型部位软骨母细胞瘤的诊断,避免误诊。

Chondroblastoma occurring in atypical sites

Objective To study the clinical, pathologic and radiologic features of chondroblastoma occurring in sites other than epiphysis and apophysis of long bones, and to investigate possible reasons for misdiagnosis. Methods The clinical, pathologic and radiologic data of 18 chondroblastoma cases occurring in atypical sites were collected from 5 major hospitals in Shanghai during the past 12 years. S 100 immunostaining was performed to confirm the cartilaginous differentiation of the tumor cells. Results Chondroblastoma occurred in small bones of feet in 10 of the 18 cases (55.6%) studied, being commonest in the talus and calcaneus bones. Mean age of the patients was 27.8 years, with 55.6% over 25 years of age. Radiologic examination revealed expansive,multilocular and well demarcated radiolucent lesions in most cases. There was local cortical destruction in 5 cases (28%) and soft tissue infiltration in 1 case. In 10 cases (55.6%), the tumor was associated with aneurismal bone cyst or simple bone cyst formation. None of the cases studied was accurately diagnosed clinically before the operation. In 2 cases,the pathology was also misdiagnosed,ofen being diagnosed as aneurismal bone cyst or giant cell tumor. Conclusions Chondroblastoma occurring in atypical sites are often associated with atypical age, radiologic features and pathologic findings at presentation. Thorough understanding of the potential pitfalls is essential in order to avoid misdiagnosis.