Fu Xinge, Jiang Juhong, Tian Xiao-ying, Li Zhi
Department of Pathology, The First Affiliated Hospital, Guangzhou Medical University, 151, Yanjiang Road, Guangzhou, 510120, China.
School of Chinese Medicine, Hong Kong Baptist University, 7, Baptist University Road, Kowloon Tong, Hong Kong, China.
Diagn Pathol. 2015 Jul 16;10:106. doi: 10.1186/s13000-015-0358-1.
Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare variant of inflammatory myofibroblastic tumor with distinctive morphological features and malignant clinical behavior. Only a few such cases have been described in the literature. We report here a case of unusual pulmonary EIMS with multiple bone metastases. A 21-year-old Chinese male patient presented with complaints of general fatigue and rapid weight loss, and a huge tumor arising in the left lower lobe of lung was detected by chest computed tomography. The mass of lung was totally resected. Microscopically, the tumor cells were rounded and epithelioid in shape. Myxoid stroma and inflammatory infiltration was also present. The tumor cells were immunopositive to anaplastic lymphoma kinase (ALK) in smooth cytoplasmic pattern. Fluorescence in situ hybridization (FISH) assay revealed the presence of rearrangement of ALK gene. Three months after lung surgery, there were multiple bone metastases and intraspinal mass found by positron emission tomography. The second surgical treatment was performed to remove the intraspinal lesion. The histological and immunohistochemical features of intraspinal mass were similar to those of pulmonary tumor. The diagnosis of pulmonary EIMS with multiple bone metastases was made. To the best of our knowledge, it may be the first case of an EIMS arising in lung. Awareness of EIMS in respiratory tract and its distinctive features is important for pathologists to avoid a diagnostic pitfall caused by histologic similarities to other ALK-positive tumors. ALK inhibitor is a promising treatment for this aggressive tumor regardless of its potential acquired resistance.
上皮样炎性肌纤维母细胞肉瘤（EIMS）是炎性肌纤维母细胞瘤的一种罕见变体，具有独特的形态学特征和恶性临床行为。文献中仅描述了少数此类病例。我们在此报告一例伴有多发骨转移的罕见肺部EIMS病例。一名21岁中国男性患者主诉全身乏力和体重快速下降，胸部计算机断层扫描发现左肺下叶有一个巨大肿瘤。肺部肿块被完整切除。显微镜下，肿瘤细胞呈圆形且为上皮样。还存在黏液样基质和炎性浸润。肿瘤细胞在胞质呈平滑模式下对间变性淋巴瘤激酶（ALK）免疫阳性。荧光原位杂交（FISH）检测显示ALK基因重排。肺手术后三个月，正电子发射断层扫描发现多发骨转移和椎管内肿块。进行了第二次手术以切除椎管内病变。椎管内肿块的组织学和免疫组化特征与肺部肿瘤相似。诊断为伴有多发骨转移的肺部EIMS。据我们所知，这可能是首例起源于肺部的EIMS病例。呼吸道EIMS及其独特特征对于病理学家避免因与其他ALK阳性肿瘤组织学相似而导致的诊断陷阱很重要。ALK抑制剂是治疗这种侵袭性肿瘤的一种有前景的方法，尽管可能存在获得性耐药。
