异位错构瘤性胸腺瘤临床病理分析

Clinicopathologic analysis of ectopic hamartomatous thymoma

目的探讨异位错构瘤性胸腺瘤(EHT)的临床病理特征、免疫表型和鉴别诊断。方法复习相关文献对3例EHT进行临床病理学和免疫组织化学分析。结果 3例EHT患者分别位于左下颈部、右锁骨上区和左锁骨上区,治疗方式均为局部手术切除。大体检查肿瘤呈结节状,界限清楚,包膜完整,切面灰白灰黄色,大小分别为2.5 cm×1.9 cm、4.5 cm×4.5 cm和3.0 cm×2.5 cm。镜下肿瘤由梭形细胞、上皮细胞和脂肪细胞3种成分构成,但以梭形细胞为主要成分。梭形细胞和上皮细胞之间可见移行。免疫组织化学检测显示梭形细胞和上皮细胞均弥漫高表达AE1/AE3、CK7、CK19和P63。随访2例患者(随访期是18个月和27个月),均未见复发和转移。结论 EHT具有特异的发病部位和组织学特征,局部完整切除是其首选的治疗方式。EHT需要和双相型滑膜肉瘤、伴有上皮分化的恶性神经鞘瘤、混合瘤、胸腺脂肪瘤等鉴别。

Objective To investigate the clinicopathological characteristics,immunophenotype and the differential diagnosis of ectopic hamartomatous thymoma （EHT）.Methods Three cases with EHT were studyed for clinicopathological and immunohistochemical features, the available literature on this subject was reviewed as well.Results The tumors of 3 patients with EHT were located at left lower neck,right supraclavicular area,and left supraclavicular area respectively,and were underwent local resection.The well-defined nodular tumors were en-capsulated with gray-yellowish cut surface,with size of 2.5 cm ×1.9 cm,4.5 cm ×4.5 cm,and 3.0 cm ×2.5 cm,respectively.Microscopi-cally,the tumors were composed of spindle cells,epithelium,and adipose tissue with the predomination of spindle cell.A gradual transition from epithelial cells to spindle cells was frequently present.Immunohistochemically,both the spindle cell and epithelial components were dif-fusely and intensely positive for AE1 /AE3,CK7,CK19,and P63.Two patients with EHT were followed up for 18 and 27 months,both without any evidence of metastasis or recurrence.Conclusion EHT is an exceedingly rare benign tumor with distinctive location and histological fea-tures and should be differentiated from biphasic synovial sarcoma,malignant schwannoma with epithelial differentiation,mixed tumor,thymoli-poma,et al.The total focal excision is the first treatment of choice for EHT.