HistopathoIogical and immunohistochemical study of non-invasive papillary urothelial tumors

ABSTRACT

Non-invasive, papillary urothelial tumors are those restricted to the level of bladder mucosa. The stage and grade are the classic prognostic variables that permit evaluating recurrence or progression of the disease. However. immunohistochcmistry is still of limited use in predicting the progress of non-invasive urothelial tumors. The present work was done to study the immuno-expression of different biologic markers in non-invasive papillary urothelial tumors graded according to WHO/ISUP classification and to evaluate their use as predictive factors for the recurrence and progression of the tumor. A total of 50 non-invasive papillary urothelial tumors constituted the material of this work; 2 papillomas, 12 papillary urothelial neoplasms of low malignant potential [PUNLMP], 2216w grade carcinomas [LGC] and 14 high grade carcinomas [HGC]. All cases were re-stained with conventional H and E, for confirming diagnosis, and with different immunostains [CK20, E-cadherin, Ki67 and p53]. Thirty six out of the 50 included cases [72%] showed abnormal CK20 immunostaining [either focal or diffuse]; mostly seen in low and high grade carcinomas. Thirty one cases [62%] showed abnormal E-cadherin immunostaini ng [heterogeneous or negative]; also seen in low and high grade carcinomas. The indices of Ki67 and p53 immunostaining were seen to be correlated with the grade of the tumor. Statistically, it was found that all the studied markers were significantly associated with tumor grade. Also, there was a significant difference between immunostaining of PUNLMP and LGC. Recurrence was seen in 16 cases [2 PUNLMP 5 LGC and 9 HGC]. However, progression to higher stage was seen in 7cases [2 LGC and 5 HGC]. From this work, we can conclude that mixed immunohistochemical staining [CK20, E-cadherin, Ki-67 and p53] of non-invasive papillary urothelial bladder tumors can help in separating PUNLMP from LGC as well as predicting recurrence and identifying potentially invasive lesions before they become actually muscle-invasive