膀胱术后梭形细胞结节临床病理观察

Clinicopathological features of postoperative spindle cell nodule of urinary bladder

目的探讨膀胱术后梭形细胞结节(PSCN)的病理和临床特征,以防误诊。方法对1例PSCH进行光镜、电镜观察并结合免疫组化、临床表现特点综合分析,同时复习文献。结果患者经尿道前列腺等离子体双极汽化电切(TUPKRP)术后22天出现尿路感染,膀胱镜检示有一个3 cm×2 cm大小的息肉样肿块。光镜下病变表面为炎性渗出及出血、坏死,底部由大量增殖的梭形细胞构成;增生细胞呈束状排列,稀疏或密集,细胞呈梭形,核浅染,异型性不明显,局部呈浸润性生长;核分裂象易见(平均15个/10 HPF),但不见病理性核分裂象;伴水肿、黏液变性及中性粒细胞弥漫浸润,未见肿瘤性坏死。免疫组化示vimentin、α-SMA、MSA、desmin、actin、CK-L均(+)。电镜显示长梭形细胞,核膜光滑,染色质细腻,核无异型性;胞质内粗面内质网丰富,胞膜下有少许短束状肌丝。术后随访36个月,未见复发。结论 PSCN形态学和临床上易误诊为恶性肿瘤,光镜特点一定要结合病史才能做出准确的诊断。

Purpose To investigate the pathological features and clinical manifestation of postoperative spindle cell nodule of bladder （ PSCN）, which may be misdiagnosed as a malignant neoplasm and undergone extensive treatment. Methods A case of PSCN was reported with the microscopic and electron microscopic findings, immuuohistochemical and clinical features. Results A patient who had the history of TUPK-RP presented with a 22-day history of painful urination and gross hematuria. Cystoscopy found a 3 cm × 2 cm polypoid tumor in the urinary bladder. Microscopic view showed a ulcerated surface and the submucosal tumor that composed mainly of myofibroblast-like spindle cells in a vascular myxoid matrix infiltrated by neutrophils. The well-developed fascicular arrangement of the proliferating cells had extreme cellularity and numerous mitotic figures （ 15/10 HPF）. While no necrosis was seen in the tumor. Immunohistochemically, the tumor demonstrated immunoreactivity for vimentin, α-SMA, MSA, desmin, actin, p53, and CK-L. Electron microscopy showed these long spindle cells had a smooth nucleus, delicate chromatin, rich rough endoplasmic reticulum, and a little short fascicular myofilament under the cell membrane. The patient was followed up for 36 months, and BUS demonstrated no evidence of tumor recurrence. The final pathological result was interpreted as PSCN. Conclusion The PSCN is easy to be misdiagnosed as malignant tumors. Urologists and pathologists should be careful to distinguish this distinct disease in order to avoid making an erroneous diagnosis. It is suggested that immunohistochemistry and clinical data are valuable in establishing a proper diagnosis.