肺微囊性纤维黏液瘤的临床病理学特征

Pulmonary microcystic fibromyxoma： report of a case with review of literature

目的探讨肺微囊性纤维黏液瘤的临床病理学特征、诊断及鉴别诊断。方法对1例发生于肺的微囊性纤维黏液瘤的临床表现、组织学形态、免疫表型及分子遗传学特征进行回顾性分析，并复习文献。结果患者女，58岁，因“咳嗽咳痰1个月余”于2014年3月入南京医科大学第一附属医院，胸部CT查见右上肺直径1．5cm孤立性结节，行肺楔形切除术。大体检查：肿瘤界限清楚，切面灰白，有黏滑感及肉眼可见的微囊，肿块紧邻肺被膜。显微镜下观察：肿瘤有广泛的黏液背景及微囊形成；肿瘤细胞为温和的梭形至星芒状，稀疏分布于纤维黏液样间质中，核分裂象难寻，未见肿瘤性坏死；间质内有丰富的小血管，也可见灶性慢性炎性细胞浸润。免疫组织化学标记显示肿瘤细胞仅波形蛋白阳性，CD34、平滑肌肌动蛋白、结蛋白、S-100蛋白、间变性淋巴瘤激酶、广谱细胞角蛋白、上皮细胞膜抗原、Calretinin、甲状腺转录因子1均阴性。荧光原位杂交示EWSR1、DDIT3及FUS基因未见断裂重组。患者术后随访38个月，未见复发或转移。结论肺微囊性纤维黏液瘤是一种罕见的富于黏液问质并伴有微囊特征的纤维性肿瘤，生物学行为暂定良性，需与其他发生于肺内伴有黏液特征的肿瘤鉴别。

Objective To study the clinicopathologic features, diagnosis and differential diagnosis of pulmonary microeystic fibromyxoma. Methods In March 2014, at the First Affiliated Hospital to Nanjing Medical University a 58-year-old female patient of pulmonary microcystic fibromyxoma was collected. The clinicopathologic, immunohistoehemical and genetic profile of a case of pulmonary microcystie fibromyxoma were studied, and the relevant literature reviewed. Results The patient was a 58-year-old female who presented with cough and sputum for 1 month. CT scan disclosed a 15 mm nodule in her right middle lobe of lung. The patient underwent a wedge resection with negative margin. Grossly, a well-demarcated peripheral lung nodule was detected, measuring 1.5 cm×1.5 cm×1.0 cm, with myxoid tan-white cut surface containing microcysts. Microscopically, the tumor was composed of bland spindled to stellate-shaped cells widely spaced within prominent fibromyxoid stroma with prominent cystic change. No mitosis or necrosis was present. There were inconspicuous slim curvilinear capillaries and occasional collection of stromal lymphocytes and plasma cells. Immunohistochemically, the tumor cells were positive for vimentin, but negative for CD34, SMA, desmin, S-100 protein, ALK, CKpan, EMA, calretinin and TTF1. Fluorescence in situ hybridization did not show chromosomal translocation involving EWSR1, DDIT3 or FUS genes. The patient was recurrence or metastasis free after follow-up for 38 months. Conclusion Pulmonary microcystic fibromyxoma is a rare benign lesion that should be differentiated from other lung tumors with myxoid characteristics.