Micropapillary urothelial carcinoma of the urinary bladder: A clinicopathological analysis of 24 cases

Abstract

Objectives: To stratify patients with micropapillary urothelial carcinoma of the urinary bladder based on the percentage of micropapillary component and to correlate tumor volume with other clinicopathological features. Methods: Cases of micropapillary urothelial carcinoma of the urinary bladder from 2002 to 2009 were identified. Only patients with available follow-up information were included in the analysis. Tumor volumes were stratified based on the percentage of micropapillary component (<50%, >50% and 100%). Results: Overall, 24 cases were analyzed. Mean patient age was 71 years (range 55-86 years), with a male to female ratio of 3:1. Six cases (6/24; 25%) were composed entirely of micropapillary component. A total of 12 cases (12/24; 50%) showed >50% micropapillary component. Six cases (6/24; 25%) showed <50% micropapillary component. A higher percentage of micropapillary urothelial carcinoma component was significantly associated with male sex, regional lymph node metastasis and pathological stage (P-values = 0.0005, 0.01 and 0.03, respectively). The percentage of the micropapillary component was, however, unrelated to patients' survival. Conclusions:The present study confirms that micropapillary urothelial bladder carcinoma is typically aggressive and presents with advanced stage disease in most cases. A quantification of the micropapillary component is to be recommended. An accurate diagnosis of this entity in relatively small biopsies or transurethral resection of bladder tumor specimens is especially critical to define the best treatment plan.

Lymphovascular Invasion in Micropapillary Urothelial Carcinoma: A Study of 22 Cases

“…4 The proportion of MPUC appears to predict poor prognosis, [12][13][14] and at least predicts high pathologic stage and lymph node metastasis. 4,5 Multiple authors 4,5,12 recommend a quantitative report of MPUC whenever it is present.…”

“…Micropapillary urothelial carcinoma occurs almost exclusively in the setting of conventional UC, 2,3 and the proportion of MPUC predicts high pathologic stage and lymph node metastasis. 4,5 The overall prognosis is poor; the 5-year and 10-year survival in the largest study were 51% and 24%, respectively. …”

“…Micropapillary urothelial carcinoma occurs almost exclusively in the setting of conventional UC, 2,3 and the proportion of MPUC predicts high pathologic stage and lymph node metastasis. 4,5 The overall prognosis is poor; the 5-year and 10-year survival in the largest study were 51% and 24%, respectively. 6 Multiple investigators have examined vascular invasion in MPUC by using immunohistochemistry for factor VIII, Ulex europaeus, CD31, and CD34, 1,7-10 as summarized in Table 1.…”

Outcome of patients with micropapillary urothelial carcinoma following radical cystectomy: ERBB2 (HER2) amplification identifies patients with poor outcome

“…[1][2][3] Several studies demonstrated that micropapillary urothelial carcinoma is diagnosed at a more advanced stage, and is associated with adverse outcome relative to typical urothelial carcinoma. [4][5][6][7][8] However, a recent study found that, although patients with micropapillary urothelial carcinoma presented at higher stage than patients with typical urothelial carcinoma, the outcomes following radical cystectomy were no different when matched for stage and other clinicopathologic variables. 9 In addition to unique histologic features, studies have shown that micropapillary urothelial carcinoma exhibits amplification of the human epidermal growth factor receptor (ERBB2 or HER2) in over 40% of cases.…”

Micropapillary Carcinoma of the Urinary Tract: A Cytologic Study of Urine and Fine-Needle Aspirate Samples

“…Most cases of urothelial MPC are associated with conventional areas of transitional cell carcinoma, and it is still not clear what percentage of micropapillary growth correlates with a poor outcome. Some authors consider that this term should be reserved for those tumors showing >50% of micropapillary growth [7], while others recommend that even a focal presence is sufficient to constitute MPC and should be mentioned in the report since it shows a more aggressive behavior [4,8]. …”