Urinary Bladder

What is your diagnosis? Perineal swelling in a dog

“…MWB are a non‐specific degenerative change, most likely composed of mucopolysaccharides or enlarged lysosomes, but unlike the inclusions observed in this case, are PAS‐positive 3 . MWB are most often associated with cells of urothelial origin, although similar inclusions have been reported in other cell types (eg, mammary, pulmonary carcinoma) 3,4 . Cytoplasmic inclusions with a similar appearance to MWB may be observed in normal, degenerating, virus‐infected, and neoplastic epithelial cell populations 3,4 …”

“…3 MWB are most often associated with cells of urothelial origin, although similar inclusions have been reported in other cell types (eg, mammary, pulmonary carcinoma). 3,4 Cytoplasmic inclusions with a similar appearance to MWB may be observed in normal, degenerating, virus-infected, and neoplastic epithelial cell populations. 3,4 Intracytoplasmic targetoid mucin vacuoles observed in human urothelial cells appear very similar to MWB but differ with mucicarmine staining.…”

“…3,4 Cytoplasmic inclusions with a similar appearance to MWB may be observed in normal, degenerating, virus-infected, and neoplastic epithelial cell populations. 3,4 Intracytoplasmic targetoid mucin vacuoles observed in human urothelial cells appear very similar to MWB but differ with mucicarmine staining. 5 Anecdotally, cytoplasmic inclusions resembling MWB have been observed in mesothelial cells, but to our knowledge, have not been documented.…”