UPK2 and breast carcinoma: If, in addition to GATA3, uroplakin II is positive for metastatic carcinoma, it should be considered as metastatic urothelial carcinoma, as has been suggested by previous studies; to the best of our knowledge, no breast carcinoma has ever been reported to be positive for uroplakin II in the English language literature [1, 3, 4].