Had a case today about EMPD which actually was an old case from last year. It made me open my notes, and voila! Another bunch of pearls of wisdom. 1. EMPD has similar features as glandular cells eg vacuolated. 2. Differential diagnosis of EMPD to keep in mind: i. Porocarcinoma ii. Bowen disease 3. However, Bowen disease is CK5/6 positive, and EMPD is negative. 4. Another useful immunohistochemistry is p63. P63 is supposed to be positive for primary EMPD and negative for secondary EMPD. Point number 4 caused me a headache because it was negative although clinically and histologically it does look like primary EMPD. But like a certain teacher once said, trust your immunohistochemistry like you trust your spouse. You can love them 100%, but you cannot trust them 100%. Holy moly!