Shariat - Figure 34

Micropapillary Variant

FIG. 34:  I will discuss 4 histologic variants that determine a more aggressive therapeutic approach in patients with T1 bladder cancer:

  • Micropapillary;
  • Sarcomatoid (carcinosarcoma);
  • Plasmacytoid;
  • Small cell carcinoma;

The micropapillary variant can be focal, extensive, or exclusive.  It has multiple papillary-type structures within single retracted spaces.  It has a very aggressive behavior with a high metastatic rate.  It is estimated that in reality >95% of these tumors with T1 high grade and a micropapillary pattern have muscle invasion already.  More than half of these patients also have demonstrable CIS.  Based on these data, Kamat and his group at MD Anderson Cancer Center (Houston, Texas) showed that these patients are best served with immediate radical cystectomy,[45] as BCG appears ineffective in these patients and understaging is often present.[46-49]  In diagnosis of muscle-invasive disease, these tumors behave differently.

References

[40]

Mochini M. Nat Rev Urol. In press

[45]

Kamat AM, Dinney CP, Gee JR, et al. Micropapillary bladder cancer: a review of the University of Texas M. D. Anderson Cancer Center experience with 100 consecutive patients. Cancer. 2007;110:62−7  https://doi.org/10.1002/cncr.22756

[46]

Memorial Sloan Kettering Cancer Center study reference needed here

[47]

Fairey AS, Daneshmand S, Lina Wang L, et al. Impact of micropapillary urothelial carcinoma variant histology on survival after radical cystectomy. Urol Oncol. 2014;32:110–6  http://dx.doi.org/10.1016/j.urolonc.2012.04.020

[48]

Wang JK, Boorjian SA, Cheville JC, et al. Outcomes following radical cystectomy for micropapillary bladder cancer versus pure urothelial carcinoma: a matched cohort analysis. World J Urol. 2012;30:801−6  https://doi.org/10.1007/s00345-012-0976-0

[49]

Meeks JJ, Taylor JM, Matsushita K, et al. Pathological response to neoadjuvant chemotherapy for muscle-invasive micropapillary bladder cancer. BJU Int. 2013;111:E325−30  http://doi.org/10.1111/j.1464-410X.2012.11751.x