伴有横纹肌样分化的前列腺间质肉瘤临床病理观察

Stromal sarcoma of the prostate with rhabdoid differentiation: clinicopathologic analyses and review of literature

目的探讨伴有横纹肌样分化的前列腺间质肉瘤(PSS)的临床病理特点与鉴别诊断。方法观察1例伴有横纹肌样分化的前列腺间质肉瘤的病理学形态及免疫表型特征,并复习有关文献。结果前列腺间质肉瘤主要由排列成束状、车辐状的长梭形细胞构成,短梭形及卵圆形细胞散在于长梭形细胞之间或弥漫成片排列,其中一些卵圆形细胞富含丰富的嗜伊红胞质、核偏位,似横纹肌母细胞。肿瘤细胞异型性明显,核分裂象多见,肿瘤内无腺性成分。免疫组化显示肿瘤细胞vimentin、CD34(+),Myo D1和myogenin散在(+)。结论前列腺间质肉瘤是一种少见的发生于前列腺特异性间质细胞的恶性肿瘤,伴有横纹肌样分化的前列腺间质肉瘤更为罕见,预后差。诊断主要依靠病史及病理组织学形态和免疫组化,鉴别诊断主要包括恶性潜能未定的前列腺间质肿瘤和发生于前列腺的横纹肌肉瘤、平滑肌肉瘤、孤立性纤维瘤、胃肠外间质瘤等。

Objective To investigate the clinicopathologic features and differential diagnosis of prostatic stromal sarcoma（ PSS） with rhabdoid differentiation. Methods Pathology and immunohistochemical stains of prostatic stromal sarcoma with rhabdoid differentiation were described,with review of the literatures. Results Microscopically,prostatic stromal sarcoma was composed of long spindle cells,which arranged in fascicles or in storiform pattern,some short spindle and oval cells scattered between the long spindle cells or diffuse distribution,in which some oval cells showed abundant eosinophilic cytoplasm,displaced nuclei like as rhabdoid cells. Cytologic atypia and mitoses were obviously seen. No glandular components were observed. Immunohistochemically,the tumor cells were positive for vimentin and CD34,and discreted cells were positive for myo D1 and myogenin. Conclusion Prostatic stromal sarcoma is fairly rare and highly aggressive tumor arising from the specialized stroma of the prostatic parenchyma,and the prostatic stromal sarcoma with rhabdoid differentiation is more rare. Its diagnosis relies mainly on histopathology and IHC which helps to distinguish from other tumors,such as prostatic stromal tumours of uncertain malignant potential,prostatic rhabdomyosarcoma,leiomyosarcoma,solitary fibrous tumor and extragastrointestinal stromal tumor.