CASE OF THE WEEK
2020-38 / September 21
Contributor: Daniel Athanazio
A man in his mid-50s underwent a 12-core prostate biopsy. Extensive glandular atrophy and basal cell hyperplasia were seen in all cores. In addition, the following focal lesion was identified:
Quiz
1. What is the correct diagnosis?
a) Acinar adenocarcinoma with aberrant p63 expression
b) Glandular atrophy, streaming pattern
c) Basal cell hyperplasia
d) Basal cell carcinoma
e) Post-atrophic hyperplasia
1. a
1. Acinar adenocarcinoma with aberrant p63 expression
Acinar adenocarcinoma with aberrant p63 expression can show distinctive morphology, often with glands, nests, and cords exhibiting atrophic cytoplasm, hyperchromatic nuclei, and prominent nucleoli, with a “basaloid” appearance. In this case, the nuclear atypia and prominent nucleoli highlighted the suspicious focus of adenocarcinoma. Figure 3 shows that the suspicious areas show only expression of p63 while adjacent benign glands also express the cytoplasmatic marker of basal cell (34be12). Immunohistochemistry was repeated only with p63, confirming the results. The suspicious areas strongly reacted for PSA (figure 5) and prostein/ P501S (not shown). GATA3 is another marker that usually stains basal cells, and was also negative in the suspicious lesion (figure 5).
Expression of PSA and prostein favor the diagnosis of acinar adenocarcinoma (with aberrant p63 expression) over basal cell carcinoma of the prostate. In addition, basal cell carcinoma should exhibit the same strong expression of high weight cytokeratins (such as 34Be12 antibody reaction) as observed for p63 (different from what is seen in figure 3).
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Wu A, Kunju LP. Prostate cancer with aberrant diffuse p63 expression: report of a case and review of the literature and morphologic mimics. Arch Pathol Lab Med. 2013;137(9):1179-1184.
Osunkoya AO, Hansel DE, Sun X, Netto GJ, Epstein JI. Aberrant diffuse expression of p63 in adenocarcinoma of the prostate on needle biopsy and radical prostatectomy: report of 21 cases. Am J Surg Pathol. 2008;32(3):461-467.
Epstein JI, Netto GJ. Differential Diagnoses in Surgical Pathology: Genitourinary System. Lippincoty Williams and Wilkins, Philadelphia, 2014.
Daniel Athanazio
Imagepat, Laboratory of Pathology
Salvador, Bahia, Brazil
Prostate
Prostate; Prostate Neoplasms; p63