Which antibodies are included in the MAIS procedure for PIN-4?

• A. CK5/14 - prostate basal/epithelial cells cytoplasmic; p63 - Basal cells Nuclear; P504S - epithelia cells - cytoplasmic
• B. CK5/14, p63, P504S
• C. CK5/14, CK7, P63
• D. p63, P504S, CK5/14

Answer: (A)

The test is about which antibodies make up the PIN-4 MAIS panel and why that combination is useful for evaluating prostatic lesions. This triple-stain set uses two basal cell markers and one neoplastic marker to distinguish benign glands from PIN or cancer. CK5/14 labels cytoplasmic basal cells in prostatic glands, showing where the basal layer is present. p63 marks basal cells in the nucleus, reinforcing identification of an intact basal layer. P504S, also known as AMACR, stains cytoplasm and is overexpressed in neoplastic prostatic epithelium.

Using all three together lets you see: glands with a continuous basal layer (positive CK5/14 and/or p63, with AMACR not overexpressed) are likely benign, while glands lacking a basal layer or showing disrupted basal staining alongside AMACR positivity point toward PIN or carcinoma. The specific trio CK5/14, p63, and P504S is what the MAIS PIN-4 panel comprises, whereas including other markers (like CK7) or omitting one of these three would not reflect the PIN-4 strategy.