Malignant myoepithelioma (myoepithelial carcinoma) of soft tissue
Malignant myoepithelioma (myoepithelial carcinoma) of soft tissue
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DOI：
10.1111/j.1440-1827.2005.01861.x
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发表时间：
2005-08-01
影响因子：
2.2
通讯作者：
Nakayama, J
中科院分区：
文献类型：
--
作者：
Harada, O;Ota, H;Nakayama, J
软组织的恶性肌上皮瘤是非常罕见的。本文报告一位17岁的男性，在他3岁时发现右前臂深部的无痛性软组织肿块。此后，它生长，没有明显的症状，如疼痛或触痛，直到他17岁时因前臂肿胀去医院就诊。一个切除的活组织检查标本显示了一个侵袭性肿瘤，表现出小叶结构。肿瘤细胞呈网状和/或小梁状排列，背景为粘液样，核固缩明显。还观察到有丝分裂和肿瘤坏死。免疫组化S-100蛋白和上皮标记呈弥漫阳性。电镜下可见微弱的细胞间连接和基底层。根据这些发现，肿瘤被诊断为恶性肌上皮瘤的软组织。六个月后，观察到多个肺转移，开放活检显示肿瘤显示相同的组织学特征，作为以前的活检标本。患者在肺活检后18个月死于疾病。对具有上皮样特征的深部软组织肿瘤应警惕恶性肌上皮瘤。
Malignant myoepithelioma of soft tissue is extremely rare. Presented herein is a case arising in a 17-year-old man. The tumor was initially noticed as a painless deep soft-tissue mass in the right forearm when the patient was aged 3 years. Thereafter, it grew without remarkable symptoms, such as pain or tenderness, until his visit to the hospital because of swelling of his forearm when he was 17 years old. An excisional biopsy specimen disclosed an invasive tumor exhibiting a lobular architecture. The tumor cells were arranged in a reticular and/or trabecular fashion with a myxoid background, and nuclear atypia was evident. Mitoses and tumor necrosis were also observed. Immunohistochemically, S-100 protein and epithelial markers were diffusely positive. Faint intercellular junctions and basal laminae were identified by electronmicroscopy. On the basis of these findings, the tumor was diagnosed as a malignant myoepithelioma of soft tissue. Six months later, multiple lung metastases were observed, and an open biopsy revealed a neoplasm displaying the same histological feature as the previously biopsied specimens. The patient died of his disease 18 months after the lung biopsy. Malignant myoepithelioma shoud be kept in mind in diagnosis of deep soft-tissue tumors with epithelioid features.