肾恶性孤立性纤维性肿瘤1例报道及文献复习

Malignant solitary fibrous tumor of the kidney:report of a case and review of the literature

目的探讨肾脏恶性孤立性纤维性肿瘤的临床病理特征、鉴别诊断及治疗和预后。方法报道1例肾恶性孤立性纤维性肿瘤的临床病理资料并复习文献。结果患者男性,56岁。临床主要表现为乏力、出汗、心慌、气短1年,以低血糖原因待查入院。CT示左肾上方及左肾前下方见3个类圆形软组织密度影,与肾分界不清,大小分别为9cm×8cm×7cm、7cm×7cm×7cm和4cm×4cm×4cm。增强后边缘轻度强化,中心不均匀强化。临床、CT检查考虑为左肾癌。行左肾癌根治术。眼观:左肾上、下极分别见一肿块,切面灰白色,部分区见有坏死,与肾界限不清。镜检:肿瘤由短梭形或卵圆形细胞组成,排列成束状、旋涡状或不规则状。部分区域血管丰富,细胞密集呈血管外皮瘤样结构;部分区域细胞稀疏伴纤维化、黏液变性。肿瘤超过60%的区域内(尤其是肾下极肿块)瘤细胞丰富密集,有异型性,核分裂象多见(>4个/10HPF),边缘呈浸润性生长,部分区可见出血坏死。免疫表型:肿瘤细胞vimentin、CD34弥漫阳性,CD99、bcl-2阳性,Ki-67增殖指数>20%。病理诊断:左肾恶性孤立性纤维性肿瘤(低度恶性)。术后随访24个月情况良好。结论肾恶性孤立性纤维性肿瘤非常罕见,确诊主要依靠病理形态学及免疫组织化学标记,并应与肾的其他梭形细胞肿瘤进行鉴别。治疗以手术完全切除为主,并注意长期随访。

Purpose To explore the clinieopathologie characteristics, differential diagnosis and treatment of malignant solitary fibrous tumor （SFT） of the kidney. Methods One ease of malignant SFT of the kidney was reported and the relevant literature was reviewed. Results The patient was a 56-year-old male presenting with weakness, sweat, fluster and shortness of breath for 1 year. The blood glucose was 2. 97 mmol/L. Hypoglycemia was the most common presenting symptom. CT scan revealed three round soft tissue masses of 9 cm × 8 cm × 7 cm,7 cm × 7 cm × 7 cm and 4 cm × 4 cm × 4 cm in the upper and front-lower of the left kidney with uneven enhancement by contrast. Clinical and CT examination considered as a renal carcinoma. The patient underwent left radical nephrectomy. Grossly,there was a mass in the upper and lower pole of the kidney respectively. The masses were poorly circumscribed with grey white color on the cut surface, and had loci of necrosis. Histopathologically,the tumors were composed of spindle-shaped cells with fascicular, storiform or haphazard arrangements. Some areas had plenty of blood vessels and hypercellularity, and showed a haemangiopericytoma-like structure. Other areas were hypocellular displaying dense collagen fibers and mucoid degeneration. More than 60% of the tumor （ especially that in the lower kidney） had high and crowded cellularity with significant pleomorphism, numerous mitoses （ mitotic count of more than 4 per 10 high-power fields） ,invasive growth in the edge of the tumor,and loci of necrosis. Immunohistochemically,the tumor cells were dif- fusely positive for vimentin, CD34, and positive for CD99, bcl-2. Ki-67 labelling index was more than 20%. The pathological diagnosis was malignant SFT of the left kidney （ low grade）. After 24 months of follow-up, the patient remained alive. Conclusions The malignant SFT of the kidney is very rare. Diagnosis is based on its pathological morphology and immunohistoehemistry. Differential diagnosis includes other spindle-shaped cell tumors of the kidney. The treatment is complete surgical resection,and a long-term follow-up is required.