A case of invasive urothelial carcinoma

―Focusing on the cytological features of urothelial carcinoma with trophoblastic differentiation―

Abstract

Background : Invasive urothelial carcinoma of the bladder with trophoblastic differentiation is usually diagnosed at an advanced stage and carries a poor prognosis. Herein, we report a case of invasive urothelial carcinoma with trophoblastic differentiation that was detected on a repeat cytopathologic review of 54 archived cases of surgically resected invasive bladder cancer.

Case : An 82-year-old woman with symptoms of cystitis was detected by ultrasonographic examination as having a tumor in the anterior wall of the urinary bladder. Urinary cytology showed papillary clusters identical to those in urothelial carcinoma, scattered giant mononuclear cells with lacy abundant cytoplasm and large nuclei containing coarse chromatin, and pleomorphic cells with multiple or hypersegmented nuclei. Histological examination of the tumor showed the features of papillary urothelial carcinoma with syncytiotrophoblast-like giant cells, muscle invasion, and lymphovascular involvement. Immunohistochemistry showed positive staining of the giant cells for HSD3B1, a specific marker of trophoblastic differentiation. The patient developed multiple distant metastases and died 3 years after surgery.

Conclusion : Urinary cytology can contribute to early diagnosis of invasive urothelial carcinoma with trophoblastic differentiation. Immunostaining using specific markers can be useful for reliable cytologic diagnosis.