Clinicopathologic analysis of ectopic hamartomatous thymoma / 局解手术学杂志

ABSTRACT

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.