Normal histology and superficial bladder lesions Flashcards
In what particular location
should the diagnosis of nested
urothelial carcinoma be cautiously made ?
- ureter
- this is because this area has a high frequency of a proliferation of von Brunn’s nests
When can a diagnosis of
atypical urothelial proliferation be made ?
- on a biopsy specimen
- when there is a proliferation of small, nested urothelial cells and the differential diagnosis includes:
- von Brunns nests vs.
- small nested urothelial carcinoma
Where would glycogenated epithelium
be more commonly found ?
- squamous metaplasia with glycogenated epithelium is often found in the trigone of the bladder in women
Why is it important to mention
if there is keratinizing squamous metaplasia ?
- keratinizing squamous metaplasia has a higher risk of development into carcinoma
What can be soft clue on biopsy
for the presence of a nephrogenic adenoma ?
- inflammation
- urothelial disruption
What is the MOST critical element
for staging urothelial carcinoma ?
- the presence or absence of invasion of the muscularis propria
- this is why you must mention the presence or absence of muscularis propria in the biopsy specimen
How are in situ flat lesions staged vs.
papillary lesions ?
- Flat lesion: pTis
- Noninvasive papillary lesions : pTa
How is staging affected by architecture
of the invasive carcinoma ?
- the staging is the same regardless of the architectural pattern of the invasive tumor
What findings on scanning of
flat epithelium hint at a normal biopsy ?
- normal thickeness urothelium (5-7 cells)
- predominantly flat
- no obvious atypia at 10x
What is the histology of normal, benign
urothelium ?
- cells are aligned in an orderly manner, perpendicular to the surface
- umbrella cells are present at the top
- but be careful, they can also be present in neoplastic processes
- benign urothelium
- dispersed chromatin
- longitudinal grooves within the nucleus
- abundant eosinophilic cytoplasm
What diagnosis are included within
the category of chronic cystitis ?
- follicular cystitis
- interstitial cystitis
- polypoid cystitis
What are the histological findings
of Follicular cystitis and what can it
be associated with ?
- well formed germinal centers within the lamina propria
- may be related to chronic inflammation associated with:
- chronic UTI
- BCG or other intravesicular chemotherapy
How is the diganosis of interstitial
cystitis rendered ?
- clinical diagnosis, usually in older women with painful bladder symptoms
- often have friable bladder mucosa on cystoscopy
- NO specific pathological findings
- Hunner ulcer
- often described in this entity
- not specific to this
- heaped up nodule with outward radiating small vessels
- generally on histology it is wedge shaped with punctate hemorrhages and granulation tissue
- Hunner ulcer
When should a diagnosis of
interstitial cystitis be rendered ?
- No topline diagnosis of this should be made
- rather it should be a descriptive biopsy with pertinent negatives including:
- CIS
- or malignancy
- Findings often seen:
- reactive epithelial atypia
- lamina propria with numerous vessels with surrounding edema
- inflammatory cell infiltrate (lymphs, plasma cells and occasional mast cells)
What are histologic features
of reactive urothelium ?
- only slightly enlarged with vesicular or dispersed chromatin and central, small but prominent nucleolus
- mitosis can be seen ofen
- usually confined to the basal part of the epithelium
- inflammtory cells can be present
- excercise extreme caution when rendering a diagnosis of dysplasia or CIS in the setting of inflammation
- reactive processes usually maintain polarity
What is a pitfall that can
mimic malignancy ?
- Malakoplakia
- reactive process
- caused by defective phagocytosis of urinary bacteria such as E. coli
- classic finding of histiocyte-rich mixed inflammation within the lamina propria
- Michaelis Gutmann Bodies
- targetoid lesions within histiocytes comprised of bacterial products
- highlighted by von Kossa calcium or iron stains
What situation typically gives rise to
pseudocarcinomatous urothelial hyperplasia ?
- generally seen in instances of pelvic radiation
- also any type of vascular insult can lead to this
- may present clinically with hematuria
Key morphologic findings:
- hemorrhage, fibrin
- fibrin thrombi in the lamina propria
- regenerative appearance to the urothelium
What is the morphology of
pseudocarcinomatous hyperplasia ?
- atypical urothelial cells which form small nests and appear to invade the lamina propria
- IMP
- nests may show retraction artifact suggestive of invasion
- urothelial cells occupy the lamina propria
- show minimal cytologic atypia and absent mitotic activity
What is the definition of flat urothelial of uncertain
malignant potential ?
- thickened urothelium with mild atypia
- mildly disoriented polarity but maturation must be preserved
- no cytologic atypia
- no mitosis
- must be flat
What condition is urothelial proliferation of uncertain
malignant potential (UPUMP) associated with ?
- generally reflects tangiential sectioning
- may be adjacent to or a precursor lesion of:
- low-grade Papillary urothelial carcinoma
If there is a flat lesion with atypia more than you expect for reactive,
what categories can be considered diagnostically ?
- atypia of unknown significance
- urothelial dysplasia
- carcinoma in situ
What is typically seen morphologically
in atypia of unknown significance and when can
the category be considered for diagnosis ?
- very subjective category
- use when atypia is concerning and cannot explain its presence, ex:
- no inflammation
- history of instrumentation
- stones
- radiation or intravesicular therapy
- the cells:
- slightly enlarged
- hyperchromatic
- mild nuclear pleomorphism
What is seen usually in
Urothelial carcinoma in situ ?
- flat lesion
- CIS
- high grade cytology with enlarged, hyperchromatic nuclei
- there is obvious disorganization
- frequent mitosis
- IMP: may be denuded, which may also serve as a clued
- cells are dyscohesive
- other types of CIS
- clinging
- pagetoid (can have an intact umbrella cell layer)
What is the normal pattern of
staining for CK20 in reactive/benign urothelium?
- generally is negative or weak subset in superficial cells
IMP: full thickness staining is more suggestive of a neoplastic lesion
