C and D, von Brunn nest with smooth contour (color-coded green), well demarcated by collagen fibers (color-coded red on MPM).
Many of the specimens that appeared cystoscopically suggestive of CIS either due to erythema or irregularity of the surface mucosa, were found to have benign pathologic features (Figure 2, A through F) such as florid proliferation of von Brunn nests or cystitis cystica et glandularis.
Urothelial carcinomas with small cystic spaces containing mucin or cell debris (Figure 1) and involvement of a von Brunn nest by urothelial carcinoma, which is not lined by columnar epithelium ("glandlike lumina"), should not be confused with adenocarcinoma.
The benign lesions include cystitis cystica, cystitis glandularis, von Brunn nests, nephrogenic adenoma, mesonephric remnant, intestinal metaplasia, and urachal remnant.
Cystitis cystica, cystitis glandularis, and von Brunn nest
hyperplasia often occur together and are thought to represent a reactive process.
Large nested variant of urothelial carcinoma: 23 cases mimicking von brunn nests
and inverted growth pattern of noninvasive papillary urothelial carcinoma.
Nested urothelial carcinoma is a specific variant of invasive urothelial carcinoma in which the invasive urothelial nests are deceptively cytologically bland and mimic von Brunn nests
(5); despite their bland cytologic features, nested urothelial carcinomas can often be deeply invasive.
Florid von Brunn nests
mimicking urothelial carcinoma: a morphologic and immunohistochemical comparison to the nested variant of urothelial carcinoma.
Von Brunn nests
in lamina propria, including cystitis cystica (Figure 2, E and F; arrow), were similarly straight forward to identify.
Cells in von Brunn nests
have slightly larger nuclei than overlying urothelial cells have.
Von Brunn nests
are aggregates of urothelial cells that represent invaginations from the surface urothelium.
The biopsy specimen showed BPEPs (PSA-positive glands) and foci of von Brunn nests