Man with a perianal ulcer, what to think?

Perianal ulcers imply a vast differential diagnosis, including in the first place squamous cell carcinoma, follow by others such as Bowen's disease, Paget disease, acuminated condyloma, metastatic gastrointestinal carcinoma, Crohn's disease, and others. We present the case of a 51-year-old man that came to the emergency room with a 5-year-evolution perianal ulcer. He referred that it started as a perianal abscess that did not improve over the time and came progressively bigger. It was always asymptomatic and did not give him any problem until 2 weeks before the consultation when it started to hurt and had some episodes of diarrhea, what motivated the consultation.