骨和软组织间叶性软骨肉瘤6例临床病理分析

Mesenchymal chondrosarcoma in bone and soft tissues:a clinicopathologic study of 6 cases

目的观察骨和软组织间叶性软骨肉瘤的临床病理特点,分析其鉴别诊断方法。方法复习6例间叶性软骨肉瘤(包括活检误诊的2例)的临床、影像学及病理学资料,进行免疫组化染色,并复习文献进行讨论。结果 6例间叶性软骨肉瘤,男女各3例;年龄21～74岁,平均38.8岁。其中3例为骨原发,2例为软组织原发,1例位于后纵隔及椎管内难以确定骨还是软组织原发。临床表现为疼痛、肿胀、局部肿块及压迫症状。影像学可见溶骨性破坏或软组织肿块伴斑点状钙化。组织学表现呈双向分化的特点,由未分化小细胞和不同分化程度的软骨以不同比例构成,可见逐渐成熟的现象。免疫组化:小细胞CD99(6/6)、vimentin(5/6)和NSE(3/6)(+);软骨S-100(6/6)(+);小细胞间质及软骨基质呈不同程度collagenⅡ(6/6)(+)。结论间叶性软骨肉瘤是一种少见的恶性肿瘤,活检标本容易误诊,须结合组织学特征、影像学表现及免疫组化表型与其他肿瘤相鉴别。collagenⅡ可以作为鉴别诊断的有用标记。

Purpose To investigate the clinicopathologic features and to analyze the differential diagnostic methods for mesenchymal chondrosarcoma in bone and soft tissues.Methods The clinical,radiological and histological features of 6 cases of mesenchymal chondrosarcoma were analyzed,including 2 misdiagnosed cases in biopsy.Immunohistochemistry was performed and related literature was reviewed.Results The group consisted of 3 male and 3 female patients whose ages ranged from 21 to 74 years,and the mean age was 38.8 years.Three cases arose in bony skeleton and 2 cases in soft tissues.One case was located in posterior mediastinum and vertebral canal and was hard to confirm the primary.Symptoms included swelling,pain and compression.Radiologically,the lesion produced lytic and destructive appearance or soft-tissue masses with stippled calcification.Histologically,the lesions were typically characterized by biphasic pattern.Undifferentiated small cells admixed with islands of hyaline cartilage with different proportion.Transition between the two components from undifferentiated to mature was observed.Immunohistochemical study showed that small round cells were positive for CD99（6/6）,Vim（5/6） and NSE（3/6）,and the cartilage was positive for S-100（6/6）.Collagen Ⅱ was positive in the extracellular tumor matrix of both the small cell areas and the cartilage areas（6/6）.Conclusion Mesenchymal chondrosarcoma is a rare malignant tumor and easy to be misdiagnosed in biopsy.Histological,radiological and immunohistochemical features should be combined to exclude other tumors.Collagen Ⅱ is a useful marker for the differential diagnosis.