软组织骨化性纤维粘液样瘤八例临床病理分析

目的：研究软组织骨化性纤维粘液样瘤（OFT）的病理形态学特点和免疫组织化学表型,并探讨其组织发生,方法：采用光镜观察（HE）和免疫组织化学标记（LSAB法）结合临床资料对8例软组织骨化性纤维粘液样瘤进行临床病理学分析。结果：8例患者均为中老年人,年龄43－78岁,平均63岁,临床上多表现为四肢近端皮下缓慢性生长的肿块,组织学上,该肿瘤归纳起来有以下3个持征性的形态,比较独特,具有诊断性意义：（1）肿瘤境界清楚,有一层厚的纤维性假包围绕,多数病例于包膜内可见一层薄的不连续性骨壳,由成熟的化生性板层骨组成;（2）肿瘤的实质由多个大小不一,细胞密度不均的小叶组成,小叶内的瘤细胞呈圆形,卵圆形或短梭形,胞质淡染或呈嗜伊红色,核染色质细致,核分裂象偶见;（3）瘤细胞呈特征性的巢状,条束状或纤细的网格六排列,肿瘤的基质呈特征性的纤维粘液样,7例行免疫组织化学标记,结果显示瘤细胞强阳性表达波形蛋白和神经元特性烯醇化酶（7／7）,多数表达S－100蛋白（6／7）,部分表达结蛋白（2／7）,7例均有随访资料,2例分别于术后2年及15年复发。结论：软组织骨化性纤维粘液样瘤是一种好发于中老年人的具潜在低度恶性的软组织肿瘤,其特征性的骨壳结构,独特的细胞形态及其排列方式具有诊断意义。免疫组织化学检测结果支持OFT起源于雪旺细胞。

Ossifying fibromyxoid tumor of soft parts: a clinicopathological analysis of eight cases

OBJECTIVE: To study the morphological characteristics and immunophenotype of ossifying fibromyxoid tumor of soft parts (OFT) with a discussion of its histogenesis. METHODS: The clinical, pathological and immunohistochemical features of 8 cases of OFT were evaluated. RESULTS: All 8 cases were middle to old aged patients, ranged from 43 -- 78 years (mean 63 years). Clinically, the majority presented as slowly growing painless masses that located in subcutis of the proximal extremities. Histologically, the tumor was characterized by the following three unique features which have diagnostic value. (1) The tumor was well circumscribed and encapsulated with an incomplete bony shell composed of metaplastic bone within the capsule in most cases; (2) The tumor parenchyma consisted of lobules of variable size and cellularity. The tumor cells within each lobule were rounded to short spindled with pale-staining or eosinophilic cytoplasm; (3) The tumor cells arranged in nests, cords, or laciform pattern, and were embedded in a characteristic fibromyxoid to collagenized stroma. Immunohistochemically, all 7 cases tested were positive for vimentin and NSE, while 6 cases expressed S-100 protein and 2 cases expressed desmin. Follow-up information showed recurrences in two patients 2 and 15 years after local excision. CONCLUSIONS: OFT is a distinctive soft tissue tumor of potentially low-grade malignancy which occurred predominantly in middle to old aged patients. The characteristic bony shell, the unique cytological appearance and arrangement of the cells are pathognomonic features of OFT. Our immunohistochemical result supported a Schwann-cell origin.