P3683 - A Rare and Rapidly Progressing Case of Squamous Cell Carcinoma of the Rectum

Rahul Patel, DO¹, Edward Bley, DO¹, Neil Patel, DO², Marisa Pope, DO¹, Joshua Soliman, DO¹, Andriy Pavlenko, MD¹, C. Jonathan Foster, DO^3
1Jefferson Health, Washington Township, NJ; ²Lehigh Valley Health Network, Allentown, PA; ³Jefferson Health, Cherry Hill, NJ

Introduction: Squamous Cell Carcinoma (SCC) of the rectum is a rare entity with limited knowledge and no clear management guidelines. It consists of 0.3% of all rectal cancers. We present a patient who came to the hospital with worsening constipation then subsequently found to have invasive SCC of the rectum.

Case Description/Methods: A 56-year-old female with a history of chronic constipation, anxiety, obesity, herpes simplex virus and hyperlipidemia arrived to the hospital with worsening constipation, tenesmus, rectal pain, left lower quadrant abdominal pain and blood-tinged stools for 6 weeks. She denied fevers, night sweats and weight loss. She has no history of smoking. She had a flexible sigmoidoscopy 1 year ago which showed internal hemorrhoids and no masses. The year prior to the sigmoidoscopy she had a colonoscopy without masses or polyps. She was hemodynamically stable on arrival. Hemoglobin was 9.5 g/dL with a normal mean corpuscular volume. Her basic metabolic panel, hepatic panel and coagulation studies were normal. CT of the abdomen/pelvis with contrast showed asymmetric thickening of the anterior and right lateral rectum measuring 4.4cm x 6.1cm with luminal narrowing. Colonoscopy during hospitalization revealed a submucosal infiltrating and ulcerated bleeding 4 cm mass of malignant appearance in the distal rectum. Biopsies of the mass resulted in tumor cells positive for p63, p16, p40, CK5/6, AE1/AE3 keratin and negative for CK7, CK20 and CDX-2 supporting a diagnosis of moderate to poorly differentiated invasive squamous cell carcinoma (figure 1). Carcinoembryonic antigen (CEA) was 5.9 ng/mL. Human immunodeficiency virus (HIV) was negative. A pelvic MRI showed 7.8cm low rectal tumor abutting the right anorectal junction and extending beyond the left mesorectal fascia. She was discharged with set up for chemotherapy and colorectal surgery follow up.

Discussion: Pathogenesis and management information of SCC is scarce. SCC of the rectum has been linked to human papilloma virus (HPV). While our case has tested positive for HPV in the past, her most recent pap smears were negative for HPV. Unfortunately, the mass was not tested for HPV DNA. It remains unclear if the two are linked for our case. However, there are no cases or literature demonstrating the speed of development of SCC of the rectum like our patient exhibited.



Disclosures:


Rahul Patel, DO¹, Edward Bley, DO¹, Neil Patel, DO², Marisa Pope, DO¹, Joshua Soliman, DO¹, Andriy Pavlenko, MD¹, C. Jonathan Foster, DO³. P3683 - A Rare and Rapidly Progressing Case of Squamous Cell Carcinoma of the Rectum, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.