Jaber Omar I, Kirby Patricia A
From the Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City.
Arch Pathol Lab Med. 2015 Nov;139(11):1459-62. doi: 10.5858/arpa.2014-0385-RS.
Alveolar soft part sarcoma is a rare neoplasm usually arising in the soft tissues of the lower limbs in adults and in the head and neck region in children. It presents primarily as a slowly growing mass or as metastatic disease. It is characterized by a specific chromosomal alteration, der(17)t(X:17)(p11:q25), resulting in fusion of the transcription factor E3 (TFE3) with alveolar soft part sarcoma critical region 1 (ASPSCR1) at 17q25. This translocation is diagnostically useful because the tumor nuclei are positive for TFE3 by immunohistochemistry. Real-time polymerase chain reaction to detect the ASPSCR1-TFE3 fusion transcript on paraffin-embedded tissue blocks has been shown to be more sensitive and specific than detection of TFE3 by immunohistochemical stain. Cathepsin K is a relatively recent immunohistochemical stain that can aid in the diagnosis. The recent discovery of the role of the ASPSCR1-TFE3 fusion protein in the MET proto-oncogene signaling pathway promoting angiogenesis and cell proliferation offers a promising targeted molecular therapy.
肺泡软组织肉瘤是一种罕见的肿瘤，通常发生于成人下肢的软组织以及儿童的头颈部区域。它主要表现为缓慢生长的肿块或转移性疾病。其特征是一种特定的染色体改变，即der(17)t(X:17)(p11:q25)，导致转录因子E3（TFE3）与位于17q25的肺泡软组织肉瘤关键区域1（ASPSCR1）融合。这种易位在诊断上很有用，因为通过免疫组织化学检测肿瘤细胞核中TFE3呈阳性。已证明，在石蜡包埋组织块上进行实时聚合酶链反应以检测ASPSCR1-TFE3融合转录本比通过免疫组织化学染色检测TFE3更敏感、更特异。组织蛋白酶K是一种相对较新的免疫组织化学染色方法，有助于诊断。最近发现ASPSCR1-TFE3融合蛋白在促进血管生成和细胞增殖的MET原癌基因信号通路中的作用，为靶向分子治疗提供了一个有前景的方向。
