A 56-year-old woman presented to her primary care physician with a 3-month history of intermittent bright red rectal blood with defecation. At her initial visit, a digital rectal examination, anoscopy, and a pelvic examination with DNA testing for high-risk human papillomavirus (HPV) were performed; all results were negative. She was referred for a colonoscopy, which revealed an abnormal area with a 3 × 4 cm mass in the rectum, 10 cm from the anal verge. Colonoscopic biopsy of this mass was consistent with invasive squamous cell carcinoma.
p16 immunohistochemistry staining of the biopsy specimen was positive. Staging workup with a total body CT scan and positron emission tomography (PET)/CT scan confirmed the presence of a rectal mass, which demonstrated a standardized uptake value of 10. There was no evidence of nodal or distant metastasis. The patient was referred to an oncologist for…
