促结缔组织增生性纤维母细胞瘤七例临床病理学分析

Desmoplastic flbroblastoma： a clinicopathologic analysis of 7 cases

目的探讨促结缔组织增生性纤维母细胞瘤的临床病理特征、免疫表型、分子遗传学改变及鉴别诊断。方法收集复旦大学附属中山医院病理科2000年1月至2016年6月期间手术切除标本病理诊断为促结缔组织增生性纤维母细胞瘤7例，进行光镜观察、免疫表型分析，并复习相关文献。结果男性2例，女性5例，年龄31—71岁（平均年龄59岁，中位年龄61岁）；四肢6例，腹腔1例。肿瘤最大径1．2～4．0cm，平均3．0cm，边界较清，质韧或硬，切面灰白色或灰白灰黄色。镜下观察2例位于真皮层，4例位于皮下，1例位于肝实质。低倍镜下在大量致密胶原纤维背景中散在分布梭形或星形肿瘤细胞，似反应性纤维母细胞。间质散在分布少量血管成分，多为薄壁小血管。高倍镜下肿瘤细胞胞质丰富，呈嗜碱性，细胞核小，深染，可见小核仁，细胞无明显异型性，未见核分裂象。7例波形蛋白均呈弥漫强阳性，结蛋白、S-100蛋白、CD34、广谱细胞角蛋白均呈阴性；仅1例α平滑肌肌动蛋白局灶阳性，余6例均阴性。Ki-67阳性指数1％-2％。4例随访11—21个月（平均16．5个月），均无瘤生存。结论促结缔组织增生性纤维母细胞瘤是一种罕见的软组织良性肿瘤，极少发生于内脏器官，诊断上需与其他良性或低度恶性的纤维母／肌纤维母细胞性肿瘤鉴别。

Objective To investigate the clinical features, immunohistochemical and differential diagnosis of desmoplastic fibroblastoma. Methods The clinical data and pathology features of 7 cases of desmoplastic fibroblastoma were collected and immunohistochemical study were carried out in all cases with a review of the literatures. Results There were 2 males and 5 females, with age ranging from 31 to 71 years （average and mean age were 59 and 61 years, respectively ）. The tumors were located in extremities and abdomen （left toe and right toe, right foot back, left leg and right thigh, right forearm and left hepatic lobe）. Clinically, the tumors presented as slow growing painless masses of long standing duration. Grossly, the tumors were well-circumscribed with firm, white to gray cut-off surface. Tumor size ranged from 1.2 to 4. 0 cm in maximum diameter （average 3.0 cm）. Microscopically, 2 cases were located in dermis, 4 cases were located in subcutaneous and 1 case was located in liver parenchyma. It was composed of spindle-shaped or stellate cells with a fibroblastic or myofibroblastic appearance, and sparsely scattered in densely fibrous or fibromyxoid background. There was small vascular component in tumor background. At high magnification, the tumor cells were medium size with abundant cytoplasm, and the nucleus were small and always with small nucleoli. In some cases, the tumor cells were slightly larger with enlarged nuclei, but without cellular atypical and mitosis. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, desmin, S-100 protein and CD34, but CKpan was negative, α-SMA showed focal positive in one case. Ki-67 index ranged from 1% to 2%. Four cases were followed-up （ranged from 11 to 21 months, average 16. 5 months） and the patients had no recurrence after surgery. Conclusions Desmoplastic firoblastoma is a rare soft benign tumor. The differential diagnosis includes other benign or low-grade fibroblastic/myofibroblastic lesions.