Interval Squamous Cell Carcinoma of the Rectum

Area of Science:

• Gastroenterology
• Oncology

Background:

• Rectal squamous cell carcinoma (SCC) is a rare malignancy with unclear etiology, though chronic inflammation and infections are suspected contributing factors.
• The incidence of rectal SCC is estimated at 0.1-0.25% per 1,000 cases, highlighting its infrequent occurrence.

Observation:

• An 82-year-old female presented with a two-month history of abdominal pain, hematochezia, and inguinal lymphadenopathy with purulent discharge.
• Imaging revealed an irregular rectal mass with significant pelvic and retroperitoneal adenopathy.
• Colonoscopy identified a large, circumferential, nonobstructing rectal lesion, further characterized by endoscopic ultrasound.

Findings:

• Histopathological analysis of a cold biopsy confirmed the rectal mass as squamous cell carcinoma (SCC).
• The findings underscore the importance of considering rare diagnoses even after unremarkable prior screenings.

Implications:

• This case highlights the diagnostic challenges and clinical presentation of rare rectal SCC.
• Further research into the pathogenesis of rectal SCC is warranted to improve early detection and treatment strategies.