Kushida Yoshio, Haba Reiji, Kobayashi Shoji, Ishikawa Masashi, Doi Takashi, Kadota Kyuichi
Department of diagnostic pathology, Kagawa University, Japan.
J Cutan Pathol. 2006 May;33(5):369-72. doi: 10.1111/j.0303-6987.2006.00424.x.
Ectopic hamartomatous thymoma (EHT) is a rare benign tumor. We present a case of EHT, which was seen as subcutaneous mass on the left supraclavicular area in a 19-year-old man. The tumor consisted of spindle cells, epithelial cells, adipose cells, and a small amount of lymphocytes, as described previously. Immunohistochemically, spindle cells were positive for keratin, a-smooth muscle actin, CD34 and vimentin, but negative for desmin and S-100 protein. Lymphocytes were positive for CD45RO but negative for CD20, CD1a, and CD99. Approximately, 5% of cells were positive for MIB-1 and no cells stained for p53 and bcl-2. Recognition of EHT is important and needs to be differentiated from high-grade sarcomas such as synovial sarcoma or glandular malignant peripheral nerve sheath tumor.
异位错构瘤性胸腺瘤（EHT）是一种罕见的良性肿瘤。我们报告一例EHT，在一名19岁男性患者的左锁骨上区表现为皮下肿块。如前所述，肿瘤由梭形细胞、上皮细胞、脂肪细胞和少量淋巴细胞组成。免疫组织化学检查显示，梭形细胞对角蛋白、α-平滑肌肌动蛋白、CD34和波形蛋白呈阳性，但对结蛋白和S-100蛋白呈阴性。淋巴细胞对CD45RO呈阳性，但对CD20、CD1a和CD99呈阴性。约5%的细胞对MIB-1呈阳性，且无细胞对p53和bcl-2染色。认识EHT很重要，需要与高级别肉瘤如滑膜肉瘤或腺性恶性外周神经鞘瘤相鉴别。
