Department of Pathology, Belfast Health and Social Care Trust, Belfast, UK.
Histopathology. 2013 Oct;63(4):545-50. doi: 10.1111/his.12205. Epub 2013 Aug 14.
Myogenin (myf4) is a nuclear transcription factor that is considered to be a sensitive and highly specific marker for skeletal muscle differentiation. Following the identification of focal strong nuclear staining with myogenin in two fibroepithelial polyps of the lower female genital tract (the index cases), we stained a series of vulvovaginal spindle cell lesions with this marker in order to investigate how widespread myogenin staining is in these lesions.
Fibroepithelial polyps (n = 13), other vulvovaginal mesenchymal lesions (n = 21) and vulval or vaginal spindle cell squamous carcinomas (n = 4) were stained for myogenin. Apart from the index cases, all of the other cases were negative, except for one vaginal spindle cell squamous carcinoma, which showed focal weak nuclear immunoreactivity. Ten of 12 embryonal rhabdomyosarcomas of the lower female genital tract were myogenin-positive, as was a single vaginal rhabdomyoma.
Our study illustrates that focal myogenin immunoreactivity occurs uncommonly in fibroepithelial polyps of the lower female genital tract. This may result in diagnostic confusion and misdiagnosis as a skeletal muscle neoplasm, especially the sarcoma botryoides variant of embryonal rhabdomyosarcoma.
肌球蛋白重链（myf4）是一种核转录因子，被认为是骨骼肌分化的敏感且高度特异性标志物。在鉴定出两个女性下生殖道纤维上皮息肉（首例）存在肌球蛋白重链的局灶强核染色后，我们用该标志物对一系列外阴阴道梭形细胞病变进行了染色，以研究肌球蛋白重链染色在这些病变中的广泛程度。
对 13 例纤维上皮息肉、21 例其他外阴阴道间叶性病变和 4 例外阴或阴道梭形细胞鳞状细胞癌进行了肌球蛋白重链染色。除首例外，所有其他病例均为阴性，仅 1 例阴道梭形细胞鳞状细胞癌呈局灶性弱阳性核免疫反应。12 例女性下生殖道胚胎性横纹肌肉瘤中有 10 例为肌球蛋白重链阳性，1 例阴道横纹肌瘤也是阳性。
我们的研究表明，下生殖道纤维上皮息肉中罕见出现局灶性肌球蛋白重链免疫反应。这可能导致诊断混淆和误诊为骨骼肌肿瘤，尤其是胚胎性横纹肌肉瘤的葡萄状肉瘤变体。
