[Clinical and pathological studies of the urothelial tumors with inverted proliferation].

We reported a case of inverted papilloma of the bladder, and six cases (two of ureteral cancer and four of bladder cancer) of transitional cell carcinoma with inverted proliferation. These tumors were superficial and pedunculated as well as transitional papilloma or ordinary papillary transitional cell carcinoma though they showed a non-papillary and polyp-like configuration. Moreover, these urothelial cancers with inverted proliferation were thought to be similar to papillary cancer with regard to grading, multiplicity, invasiveness and recurrence. Therefore, transurethral resection or segmental ureterectomy may be recommended for the tumor of low grade malignancy and radical treatment including systemic chemotherapy may be recommended for the tumor of high grade malignancy.