Fouzia Rahman, 1, Muhammed G. Nathani, MD, FACG2 1UTMB, Galveston, TX; 2Kelsey Seybold Clinic, Spring, TX
Introduction: Anorectal malignant melanoma (MM) is exceedingly rare. The prognosis is poor, and the treatment is controversial. We report a case of anorectal MM in an otherwise healthy gentleman. We decided to initiate treatment with immunotherapy with check point inhibitors. Unfortunately, he succumbed to immunotherapy related myocarditis.
Case Description/Methods: A 70-year-old Caucasian male presented with a 4 week history of rectal pain and bleeding. He had a colonoscopy 2 years prior. His physical exam was normal except a palpable firm mass on digital rectal exam. Colonoscopy demonstrated a 4 cm friable, ulcerated and partially necrotic malignant appearing mass in the distal rectum, originating from the anorectal junction. The biopsies confirmed the diagnosis of Malignant Melanoma. A PET scan showed a 4.1 cm hypermetabolic mass at the anorectal junction and a 2 cm hypermetabolic metastatic lymph node in the right internal iliac region. The initial plan was to have surgery followed by radiation/chemotherapy. A tertiary care oncology opinion was obtained, along with a discussion at the tumor-board and at the regional colorectal surgical scientific meeting. The decision was made to start with immunotherapy with check point inhibitors (Nivolumab/Ipilimumab), followed by radiation treatment, and then surgery. On day 10 after infusion, he had facial swelling and skin rash. He then became short of breath and was admitted to the hospital with elevated troponin. The cardiac catheterization did not show any obstructive coronary disease. A diagnosis of myocarditis was made. He had a rapidly evolving hospital course with multi-organ failure, cardiac arrhythmia followed by cardiac asystole that did not respond to CPR.
Discussion: Anorectal malignant melanoma is a very rare disease with a poor prognosis. The treatment modalities are controversial and not standardized, which is a dilemma for the treatment team. The traditional treatment for early-stage disease has been surgery, with utilization of radiation/chemotherapy for more advanced disease. The development of immune checkpoint inhibitors such as Ipilimumab and Nivolumab have made a significant impact in the treatment of cutaneous malignant melanoma, but the data is extremely sparse on the anorectal MM because of the rare and aggressive nature of the tumor. There is a significant side effect potential of check point inhibitors, but myocarditis is relatively rare. More research into new approaches of immunotherapy and targeted therapy is needed.
Fouzia Rahman indicated no relevant financial relationships.
Muhammed Nathani indicated no relevant financial relationships.
Fouzia Rahman, 1, Muhammed G. Nathani, MD, FACG2. P0238 - Treatment Dilemma for Anorectal Malignant Melanoma, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.