Prostein (p501s) is expressed in primary extramammary Paget disease

Area of Science:

• Dermatopathology
• Oncology
• Uropathology

Background:

• Extramammary Paget disease (EMPD) is an intraepidermal carcinoma affecting the skin of the urogenital, perineal, and perianal regions.
• EMPD can be primary (arising in the skin) or secondary (metastatic from other cancers like urothelial or colorectal).
• Prostein (p501s) is a marker typically associated with prostatic epithelial cells and adenocarcinoma.

Purpose of the Study:

• To investigate the expression of prostein in primary EMPD, secondary EMPD, and mammary Paget disease (MPD).
• To evaluate prostein's utility as an immunohistochemical marker for differentiating primary EMPD.

Main Methods:

• Immunohistochemistry was used to detect prostein expression.
• The study analyzed tissue samples from patients with primary EMPD, secondary EMPD, and MPD.
• Expression of GATA3 and androgen receptor (AR) was also assessed in primary EMPD cases.

Main Results:

• Prostein was positive in all tested cases of primary EMPD (11/11), including invasive and non-invasive components and a nodal metastasis.
• Prostein was negative in all cases of mammary Paget disease (0/11) and secondary EMPD (0/5).
• Primary EMPD cases showed varying degrees of prostein staining and also expressed GATA3 and androgen receptor (AR).

Conclusions:

• Prostein demonstrates high sensitivity and specificity for primary EMPD.
• Prostein is a potentially valuable immunohistochemical marker for diagnosing primary EMPD.
• This finding aids in distinguishing primary EMPD from secondary EMPD and MPD.