Sonia Agarwal1, Atul Tiwari2, Mohan Lal Yadav3
BACKGROUND
Differentiating prostate carcinoma (PCa) arising in the neck of urinary bladder from
high grade urothelial cancer (UCa) with prostatic extension can be a difficult task
for histopathologist due to similar morphologic characteristics and overlapping
clinical manifestations in the two diseases. These two tumours often occur in
association with one another but have different potential therapeutic strategies
and prognostic implications. We have investigated p63 immunohistochemical
(IHC) marker as simple first line marker adjuvant to histopathological examination.
METHODS
In this prospective study, total 50 cases including 25 cases of urothelial carcinoma
and 25 cases of prostatic carcinoma were taken. Tumour grade was determined
according to standard H&E staining and scoring system. p63 expressions were
determined by immunohistochemical staining of all the cases. The obtained results
were analysed and evaluated using chi-square statistical test to determine whether
p63 IHC can be used as simple first line marker tool with a high sensitivity and
specificity.
RESULTS
p63 was not expressed in any of the 25 cases of prostatic carcinoma cases while
in urothelial carcinoma it was expressed in 23 of 25 (92 %) cases. p63 IHC staining
expression is positive in all histological grades of urothelial carcinomas. 2 out of
25 cases of urothelial carcinomas were negative for p63 IHC expression. None of
the prostatic adenocarcinomas expressed p63 staining. Sensitivity of p63 stain in
differentiating UCa with PCa was 92 % in our study, specificity of p63 stain in
differentiating UCa with PCa was found to be 100 %.
CONCLUSIONS
p63 can be used as a screening first line IHC marker to distinguish urothelial
carcinomas from prostatic adenocarcinomas. For challenging and unresolved cases
both of these have limited sensitivity; thus, authors recommend two lineagespecific
markers one each for UCa (GATA3, S100P) and PCa (NKX3.1, P501S,
PSMA) should be used for definitive diagnosis.
