Keelawat Somboon, Shuangshoti Shanop, Kittikowit Wipawee, Lerdlum Sukalaya, Thorner Paul S
Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Pediatr Dev Pathol. 2009 Jul-Aug;12(4):301-6. doi: 10.2350/08-11-0557.1.
Epithelioid sarcoma is a rare soft-tissue tumor that usually occurs in young adults, with a median age of 26 years. This malignancy has been divided into distal and proximal types. The latter is found in proximal body sites including the head and neck region. We present a rare case of parotid proximal-type epithelioid sarcoma in a 1-year-old male child; this is the 4th reported case in the literature and the youngest in a pediatric patient to date. The tumor showed prominent rhabdoid features by light microscopy. Immunohistochemical studies revealed positive staining to cytokeratin (AE1/AE3), epithelial membrane antigen, vimentin, and BAF47. Thus, while the tumor resembled a malignant rhabdoid tumor, the positive staining for BAF47 supported instead a diagnosis of epithelioid sarcoma, according to our current understanding of these 2 tumor types. Also, the clinical course was not the typical aggressive behavior of a rhabdoid tumor. The patient underwent radical parotidectomy without adjuvant therapy and remained disease-free at follow-up, 14 months after surgery.
上皮样肉瘤是一种罕见的软组织肿瘤,通常发生于年轻人,中位年龄为26岁。这种恶性肿瘤已分为远端型和近端型。后者见于身体近端部位,包括头颈部区域。我们报告1例1岁男童腮腺近端型上皮样肉瘤的罕见病例;这是文献报道的第4例,也是迄今为止儿科患者中最年幼的1例。光镜下肿瘤显示明显的横纹肌样特征。免疫组化研究显示细胞角蛋白(AE1/AE3)、上皮膜抗原、波形蛋白和BAF47呈阳性染色。因此,虽然该肿瘤类似恶性横纹肌样肿瘤,但根据我们目前对这两种肿瘤类型的认识,BAF47阳性染色反而支持上皮样肉瘤的诊断。此外,临床病程并非横纹肌样肿瘤典型的侵袭性行为。患者接受了根治性腮腺切除术,未进行辅助治疗,术后14个月随访时无疾病复发。