肺上皮样炎性肌纤维母细胞肉瘤临床病理观察

Pulmonary epithelioid inflammatory myofibroblastic sarcoma: report of a case and review of literature

目的提高对肺上皮样炎性肌纤维母细胞肉瘤的认识。方法报道1例罕见的肺上皮样炎性肌纤维母细胞肉瘤,进行组织形态学观察及免疫组化检查,并结合相关文献进行讨论。结果患者青年男性,21岁。体检发现左下肺肿物,行"左下肺叶切除并肺门及纵隔淋巴结清扫术",术后2个月出现双下肢麻木、右下肢活动障碍及排尿困难。PET-CT示全身弥漫性骨及骨髓内肿瘤转移。肺部肿物镜下呈胖梭形的纤维母细胞与肌纤维母细胞混杂排列,有黏液样基质及多量炎细胞浸润。局灶细胞呈上皮样,胞质丰富嗜双色性,胞核常偏位,泡状核,可见单个明显核仁,并见大量神经节样细胞。细胞异型性明显,核分裂>4个/10HPF,并有较多多核巨细胞及灶性坏死。转移灶均为异型的上皮样细胞及神经节样细胞伴明显的黏液样基质,核分裂>10个/10HPF,病理性核分裂多见。免疫组化示梭形细胞区及上皮样细胞区瘤细胞vimentin、ALK、SMA及EMA均(+),部分瘤细胞p53(+),上皮样区Ki-67增殖指数40%。患者出院20天后死亡。结论肺上皮样炎性肌纤维母细胞肉瘤罕见,诊断时需与未分化大细胞癌、ALK阳性的间变性大细胞淋巴瘤及其他类型肉瘤鉴别。正确诊断对临床制定合适的治疗方案非常重要。

Objective To improve the knowledge of pulmonary epithelioid inflammatory myofibroblastic sarcoma. Methods A case of rare pulmonary epithelioid inflammatory myofibroblastic sarcoma was analyzed by histological observation and immunohistoehemieal examination, and the related literatures were reviewed. Results A 21 years old male revealed a left lower lung tumor by physical examination. Removal of the left lower lobe and hilar and mediastinal lymphadeneetomy＂ was done. Two months later, double lower limb numbness, fight lower limb movement disorder and dysuria were oceured. PET-CT showed diffuse bone and bone marrow metastasis. Pulmonary masses were gray-white, local gray pink on the gross. Histology showed fat spindle fibroblasts and myofibroblasts were mixed, with myxoid stroma and large quantities of inflammatory infiltration. Focal cells were epithelioid with abundant amphophilic cytoplasm, nucleus often offset, with vesicular nuclei, and prominent nucleoli, and a large number of ganglion-like cells could be seen. Cell atypia, mitosis 〉 4/10HPF, more multinueleated giant cells and focal necrosis were noted. Metastatic lesions of bone marrow were atypical epithelioid cells and ganglion-like cells with a obviously myxoid stroma, mitosis 〉 10/10HPF and pathological mitosis could be seen frequently. Immunohistochemistry of spindle cells and epithelioid cell region showed the expression of vimentin, ALK, SMA and EMA, some tumor cells were positive for p53, and Ki67 index in the epithelioid area were about 40%. The patient was died after fellow-up for 20 days. Conclusion Pulmonary epithelioid inflammatory myofibroblastic sarcoma is rare, which should be distinguished from large cell undifferentiated carcinoma, ALK positive anaplastie large cell lymphoma and other types sarcoma. Correct diagnosis is very important to decide clinical treatment plan appropriately.