Lobulated inverted papilloma of the ureter

Inverted urothelial papilloma of the upper urinary tract: description of two cases with systematic literature review

BACKGROUND

Inverted urothelial papilloma (IUP) of the upper urinary tract is an uncommon benign tumour that occasionally presents as a polypoid mass causing urinary obstruction. Histologically, IUP is characterised by a proliferating urothelium arranged in cords and trabeculae, in continuity with overlying intact epithelium, and extending into the lamina propria in a non-invasive, endophytic manner. Cytological atypia is minimal or absent. Top differential diagnoses include urothelial carcinoma with inverted growth pattern and florid ureteritis cystica. Although urothelial carcinomas of the upper urinary tract with prominent inverted growth pattern commonly harbour microsatellite instability, the role of the mutator phenotype pathway in IUP development is still unclear. The aim of this study was to describe two additional cases of IUP of the upper urinary tract, along with an extensive literature review.

CASE PRESENTATION

We observed two polypoid tumours originating in the renal pelvis and the distal ureter, respectively. Both patients, a 76-year-old woman and a 56-year-old man, underwent surgery because of the increased likelihood of malignancy. Histology was consistent with IUP and patients are alive and asymptomatic after long-term follow-up (6 years for the renal pelvis lesion and 5 years for the ureter lesion). The tumours retained the expression of the mismatch-repair protein MLH1, MSH2, and PMS2 whereas loss of MSH6 was found in both cases.

CONCLUSIONS

When completely resected, IUP does not require rigorous surveillance protocols, such as those for urothelial carcinoma and exophytic urothelial papilloma. It is therefore important for the surgical pathologist to be aware of this rare entity in order to ensure correct patient management.

[Can inverted papilloma in urinary bladder be considered as a benign tumor]

Inverted papilloma of the urinary bladder is a rare entity. According to literature data, this disease is not malignant, and has low recurrence rate. Authors studied cases detected at the Urology Department and Urooncological Centrum at Semmelweis University in the last 11 years. They aimed to find out the rate of inverted papilloma recurrences, and transformations into malignant bladder cancer.

MATERIALS AND METHODS

Thirty patients with histologically proven inverted papilloma were followed after transurethral resection of bladder, which meant urine tests every three months, abdominal ultrasound and cystoscopy. After a year, these examinations were done in every six months.

RESULTS

Three patients presented transitiocellular carcinoma (17, 60, 92 months later) during this period. In one case, inverted papilloma and transitiocellular tumor (pTa G1) were detected. In one patient, inverted papilloma was found by control cystoscopy after transurethral resection of bladder (pT1 G2) and local chemotherapy 15 months later.

CONCLUSIONS

Based on authors' experience, inverted papilloma of the urinary bladder is a benign lesion, but malignant changes or concomitant transitiocellular tumor may occur, thus follow-up is needed. Although references are not standardized, authors suggest following patients with inverted papilloma as a primary (pTa G1) bladder cancer.

Inverted papilloma of the ureter with malignant change

Three patients with inverted papilloma of the ureter are described. A range of histological features was seen, including one showing malignant change. This condition, which is probably more common than previously thought, can be successfully treated by conservative surgery and close follow-up.

Multiple simultaneous inverted papillomas of the upper urinary tract. A case report with a review of ureteral and renal pelvic inverted papillomas

An asymptomatic 73-year-old woman was found to have multiple, simultaneous, inverted papillomas of the renal pelvis and ureter. A review of the world literature yielded 34 cases of inverted papillomas in the upper urinary tract: 13 in the renal pelvis, and 21 in the ureter. Among these 34 cases, there were 26 male and five female patients, with gender not given for three others. Patients ranged in age from 19 to 89 years (mean, 64.1 years). Many cases lacked complete clinical details but, among the others, gross painless hematuria was the presenting symptom in seven; hematuria with flank pain or colic in six; and pain without hematuria in six. Only six patients lacked urinary tract symptoms, and three of these had microscopic hematuria. Only two patients had more than one inverted papilloma, and these were not multicentric. Adequate pathologic documentation and follow-up data were, unfortunately, absent in many of the cases. Although inverted papillomas are curable with surgical resection, with a low rate of local recurrence, they appear to be associated with synchronous or asynchronous carcinomas, especially other transitional cell tumors in the urinary tract.

Inverted papilloma: an uncommon benign cause of a ureteral filling defect

A case of inverted papilloma of the ureter in a 62-year-old man is presented along with a literature review of 14 cases. This rare benign tumor should enter the differential diagnosis of a ureteral filling defect especially when it has a smooth configuration. Preoperative consideration of this diagnosis may lead to intraoperative confirmation of pathology and conservative resection.

Inverted papilloma with intussusception of the ureter. Case report

A case of inverted papilloma with intussusception of the ureter is reported. The patient is followed up 5 years after conservative treatment by partial resection of the ureter. No signs of urothelial tumor in the upper urinary tract or urinary bladder were revealed.

Inverted papilloma of upper urinary tract

Two new cases of inverted urothelial papilloma in the upper urinary tract are described and added to the 22 cases previously reported in the literature. In both cases inverted papilloma was localized beneath macroscopic normal surface, and in one of the cases the changes were found scattered widely in the upper urinary tract. The possible etiology and the symptomatology are discussed, and the need for follow-up of these patients is emphasized.

Inverted papilloma of ureter

A rare case of inverted papilloma of the ureter in a sixty-eight-year-old man is presented, and the literature is reviewed.

Inverted papilloma of the urinary tract

We report 9 clinicopathological cases of inverted papilloma. The occurrence of associated true malignant epithelial tumors in the urinary tract in 4 patients is not concurrent with previous reports. Even though inverted papilloma per se is a benign lesion it may be associated with malignant epithelial tumors of the urinary tract. The similarity between proliferative lesions of the bladder and inverted papilloma is discussed. The possibility of common etiologic factors of proliferative cystitis, cystitis cystica, cystitis glandularis, inverted papilloma and ordinary bladder tumors may be considered.