S4926 Two Rare Cases of Perianal Disease Associated Malignancy in Crohn's Disease Patients

Introduction: Perianal fistulizing disease is seen in 20% of Crohn’s Disease (CD) patients. Rarely, chronic perianal disease can lead to the development of perianal cancer. Here, we report on 2 cases of inflammatory bowel disease associated perianal cancer diagnosed at the same tertiary care center within 6 months of each other. Case Description/Methods: A 63-year-old man with a history of ileocolonic penetrating/stricturing CD with perianal fistulas and abscesses (on Remicade) presented for increased fistula drainage. He had been on chronic antibiotic therapy for 2 years which had recently been discontinued. He subsequently developed increased drainage that did not improve with resumption of antibiotics. Computed tomography (CT) abdomen showed worsening fistulas and abscesses. His most recent colonoscopy 3 months prior showed endoscopic remission. Exam under anesthesia (EUA) with biopsy was performed. Pathology showed signet ring cell carcinoma of colorectal origin. His tumor was unresectable due to the extent of fistulous tracts. A diverting loop ileostomy was performed, and the patient is currently receiving FOLFOX chemotherapy. A 68-year-old man with a history of penetrating ileocolonic CD with small bowel perforation and subsequent transverse loop colostomy, perianal fistulas, and hidradenitis suppurativa was evaluated for an open, bleeding fistula. Wound culture grew multi-drug resistant bacteria. CT showed a left buttock multiloculated abscess which was increasing in size from prior imaging. The CT also showed left inguinal lymphadenopathy, multiple splenic lesions and pulmonary nodules concerning for malignancy. EUA with biopsy of the left buttock wound revealed moderately differentiated squamous cell carcinoma. His last colonoscopy 3 years prior showed endoscopic remission and minimal chronic inflammation on pathology. The patient was planned for chemotherapy but passed away from complications of sepsis secondary to wound infection before therapy could be initiated. Discussion: Although perianal malignancy is a rare complication of perianal CD, this diagnosis must be considered in patients with worsening perianal disease that is resistant to treatment. Early referral for EUA and biopsy is essential to making a diagnosis. The risk of perianal cancer is increased in patients who smoke, have a history of HPV infection, and who have perianal disease greater than 10-year duration. It is important to remember that the degree of perianal disease does not necessarily correlate with luminal disease.