USE OF P63 IN ASSESSING
MIMICS OF PROSTATIC
ADENOCARCINOMA
DR. A. T. ATANDA, BAYERO
UNIVERSITY/AMINU KANO TEACHING HOSP.
KANO
BACKGROUND
Prostatic carcinoma has several well
documented mimics, particularly on core
needle biopsy, for which the pathologist
cannot rely on morphology alone for
their differential diagnosis.
 Correct evaluation of these mimics will
help prevent unnecessary treatment for
cancer.

Mimics of Prostatic Carcinoma
Atrophy
Basal Cell Hyperplasia
Adenosis
Seminal vesicles
Ganglia
Paraganglia

AIM
To evaluate the reliability
of morphology alone
measured against
immunohistochemistry in
evaluating equivocal
prostatic biopsies.

METHODOLOGY
p63 immunohistochemical stain (clone
BC4A4)
 equivocal impressions of benign versus
malignant diagnoses over a
 12-month period (Jan – Dec., 2013)
 Negative stain = positive for malignancy
 Positive stain = negative for malignancy

Criteria for diagnosis of CaP
Major criteria
 infiltrative acini which may have cribriform
disposition
 absence of basal cells; and
 nuclear and/or nucleolar enlargement.
Minor criteria included: adjacent high grade
PIN and nuclear hyperchromasia
 others
 mucinous fibroplasia, perineural invasion and
glomerulations
Results
61 cases of CaP
 27(44.3%) were considered
equivocal.
 6 (22.2%) of the 27 showed basal cell
staining
 3 cases of atrophy
 basal cell hyperplasia
 clear cell cribriform hyperplasia
 Urothelium

Results
The probability of erroneous
interpretation ranged btw
8.7% and 42.3%

PPV of morphology alone was
77.8%.

RESULT ctd



Sensitivity of 100% (83.8% to
100%);
Specificity of 77.8% (57.7% to
91.3%);
NPV of 100%.
Discussion
Our study
 22.2% reclassified; Error rate 8.7%
(sensitivity:77.8%; specificity: 100%)
 7.5% error rate reported by Berney et
at1 (London)
 1.3% documented by Epstein et al2 in the
US
 100% and 64%.3

Reasons for lower
specificity by morphology
Surgeons
Sample adequacy (volume &
number)
Crush artifacts
Cauterization artifacts
 Pathologists
Good sections
inexperience

Discussion

The use of immunohistochemical staining for p63
protein alone, or as a component of a cocktail
comprising
p63,
alpha-methyl-CoA-racemase
(AMACR) and Cytokeratin CK903,3 is also gaining
momentum.
conclusion

For improvement in diagnosis of
carcinoma of prostate, particularly
from core needle biopsies, there is
need for pathologists to pay
attention to the common mimics of
carcinoma and incorporate
immunohistochemistry into their
diagnostic armamentarium.
References
1. Berney DM, Fisher G, Kattan MW, Oliver RT, Møller H, Fearn P, et al; Trans-Atlantic
prostate group. Pitfalls in the diagnosis of prostatic cancer: retrospective review of 1791 cases
z
with
clinical outcome. Histopathology 2007; 51: 452-7.
2. Epstein JI, Walsh PC, Sanfilippo F. Clinical and cost impact of second-opinion pathology:
review of prostate biopsies prior to radical prostatectomy. Am J Surg Pathol 1996; 20: 851-7.
3. Tokumaru Y, Harden S V, Sun D I, Yamashita K, Epstein J I, Sidransky D. Optimal use of a
panel of methylation markers with GSTP1 hypermethylation in the diagnosis of prostate
adenocarcinoma. Clin Cancer Res 2004; 10: 5518-22.