Ectopic intestinal mucosa implanted on the perianal skin of a patient with Crohn disease

Intestinal mucosa implanted in skin is an exceedingly rare occurrence. Implantations are thought to occur during the creation of ostomy sites or other surgical procedures in which suture goes through bowel mucosa and then skin. Current ostomy literature reports this as a very uncommon complication. We present a 54-year-old man diagnosed with Crohn disease with severe perianal involvement who was referred to our outpatient clinic because of two persistent perianal cutaneous ulcerations. He previously underwent several interventions to drain complex perianal fistulas and abscesses, the last of them involved placing seton stitches to ensure continuous draining during the healing process. Physical examination revealed two painful ulcerations with bleeding on contact. A skin biopsy was performed, revealing ectopic intestinal mucosa with crypts, villi, and goblet cells. Perianal ulcerations characteristic of Crohn disease might be difficult to differentiate from ectopic implant of bowel mucosa secondary to a surgical procedure in the perianal area. Therefore, we believe a high degree of suspicion and skin biopsy are key to the diagnosis.