Micropapillary Carcinomas of Bladder Referred to Hasheminejad Kidney Center in a Five Years Period, Case Series and Review of Literature

Introduction:Micropapillary variant of urothelial carcinoma is a rare variant of urothelial carcinomaandhas micropapillary architecture, which is reminiscent ofthe papillary configuration seen inovarian papillary serous tumors. There are several important reasons for recognizingmicropapillary variant of urothelial carcinoma includingits aggressive behavior, invariablyhigh grade and usually highstage of the tumor and frequent association with vascular–lymphatic invasion.Case series:Over a period of 5 years, 8 cases of micropapillary carcinoma of bladder were diagnosed inHasheminejad Kidney Center. Seven cases were male. The mean age of patients was 70 yearsold.Four cases had almost pure micropapillary features. The other four cases were mixture ofpapillary andmicropapillary pattern. All 8 cases were high grade muscle invasive tumors.Three of them were associated with carcinoma insitu. Subsequently three of them wereundergone radical cystectomy. All 3 cases had multiple lymph node metastasis andlymphovascular invasion.For the only case which occurredin a 70 years old female, theimmunohistochemicalstainings proved the urothelial origin of tumor and ruled out theovarian or breast origin of tumor.Literature review and conclusion:This rarehistological variant shows a definite male predominance which is higherthan inconventional urothelial carcinoma. The percentage of micropapillary component has beenshown to be a significant adverse prognostic factor. Urothelial carcinoma in situ isdemonstrable in more than 50% of the cases. The metastaticsites of tumors with amicropapillary component arepredominantly composed of tumors with this histologicalpattern. The presence of micropapillary histology in metastatic sites should promptconsideration of the possibility of urothelial carcinoma,especially if the micropapillaryconfiguration isencountered in the peritoneum, abdominal lymphnodes or mesentery of amale patient with anunknown primary or in a female with normalappearing ovaries. Ifthebiopsy is superficial and lacks muscularispropria, there should be a suggestion for a rebiopsyand reevaluation for staging. The reporting of this variant in biopsies or TUR-Bspecimens would give a signal of early cystectomy for pTa and pT1tumors and overally moreaggressive treatment for these tumors.

کلیدواژه ها:

Micropapillary ، Carcinoma ، Urothelial ، Bladder