St. Luke's Hospital Chesterfield, MO, United States
Balakrishna Ravella, MBBS, MD1, Albert Manudhane, MD2, Breton Roussel, MD3, Chung Sang Tse, MD2, Sarah M. Hyder, MD, MBA4, Harlan Rich, MD2 1St. Luke's Hospital, Chesterfield, MO; 2Warren Alpert Medical School of Brown University, Providence, RI; 3Warren Alpert School of Medicine, Brown University, Providence, RI; 4Warren Alpert Medical School of Brown University, East Providence, RI
Introduction: Primary rectal squamous cell carcinoma (SCC) is an extremely rare malignancy with an incidence of approximately 0.10 - 0.30 per 1,000 colorectal malignancies. We discuss a patient diagnosed with primary rectal SCC presenting as new onset hematochezia.
Case Description/Methods: A 67-year-old male with a history of atrial fibrillation (not on anticoagulation) presented to the emergency department with abdominal cramping, lightheadedness, fatigue and new-onset rectal bleeding. Examination revealed a palpable rectal mass and non-thrombosed external hemorrhoids. Hemoglobin had dropped 6 g/dL from baseline. Colonoscopy demonstrated a submucosal, ulcerated partially obstructing mass in the distal rectum, 1cm proximal to the anal verge, involving one-third of the lumen circumference with active oozing (Figure A). The endoscopic view of this mass had a submucosal appearance, suspicious for a stromal lesion; however, an Endoscopic ultrasound (EUS) revealed an 8.5 x 5.1 x 4 cm hypoechoic mass arising from the rectal muscularis mucosa (Figure B). MRI pelvis displayed extensive mesorectal and left internal iliac chain lymphadenopathy. Both endoscopic mucosal biopsies and EUS-guided fine needle biopsy revealed moderately differentiated invasive SCC. The patient is currently undergoing treatment with 5-Fluorouracil, mitomycin, and radiation therapy.
Discussion: Most primary rectal cancers are adenocarcinoma. Rectal SCCs account for 0.1 - 0.3% of rectal cancers, about 90% of colorectal SCCs, often arise from the anoderm rather than from the rectal mucosa proximal to the anal verge.
The symptomatology and presentation of rectal SCC is similar to adenocarcinoma and includes new onset hematochezia, abdominal cramping or pain, with or without weight loss. Most patients are diagnosed with local or locoregional disease but have a poorer survival when compared with patients with rectal adenocarcinoma at the same stage.
Historically, rectal SCCs were treated similarly to adenocarcinoma with surgical resection. Recent studies showed benefit with chemoradiation alone. A systematic review (Guerra et al. 2016) reported a pooled overall survival of 86% with chemoradiation compared to 48% with surgery. The overall 5-year survival for rectal SCC was found to be 48.9% compared with 62.1% for adenocarcinoma.
In conclusion, though rectal SCC is a rare malignancy, clinicians should consider this as a differential in patients presenting with hematochezia and a rectal mass.
Figure: A. Colonoscopy showing an ulcerated rectal mass with active oozing B. EUS consistent with a mass in the rectal muscularis mucosa
Disclosures: Balakrishna Ravella indicated no relevant financial relationships. Albert Manudhane indicated no relevant financial relationships. Breton Roussel indicated no relevant financial relationships. Chung Sang Tse indicated no relevant financial relationships. Sarah Hyder indicated no relevant financial relationships. Harlan Rich indicated no relevant financial relationships.
Balakrishna Ravella, MBBS, MD1, Albert Manudhane, MD2, Breton Roussel, MD3, Chung Sang Tse, MD2, Sarah M. Hyder, MD, MBA4, Harlan Rich, MD2. P0154 - A Case of Primary Rectal Squamous Cell Carcinoma: An Unusual Gastrointestinal Malignancy, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.