Nonmass-Forming Type Anocanal Cancer With Pagetoid Spread With a Challenging Differential Diagnosis: A Case Report

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Pagetoid spread (PS) of anorectal cancer is rare and linked to a poor prognosis.
• Distinguishing PS from Extramammary Paget disease is challenging, especially in nonmass-forming anorectal cancer.
• Accurate differentiation is vital due to differing treatment strategies and prognoses.

Purpose of the Study:

• To highlight the diagnostic challenges in differentiating nonmass-forming anorectal cancer with PS from Extramammary Paget disease.
• To emphasize the importance of immunohistochemical staining in accurate diagnosis.
• To report a case illustrating these diagnostic considerations.

Main Methods:

• Case report of a 79-year-old woman with a perianal skin eruption.
• Endoscopic examination revealing an ulcerated lesion in the anal region.
• Biopsy and immunohistochemical analysis (CK7, CK20, CDX2, GCDFP-15) for diagnosis.
• Surgical resection (laparoscopic abdominoperineal resection) and lymph node dissection.

Main Results:

• The patient was diagnosed with nonmass-forming anorectal cancer with PS.
• Immunohistochemical staining confirmed the diagnosis.
• Postoperative analysis validated the findings.

Conclusions:

• Accurate differentiation between anorectal cancer with PS and Extramammary Paget disease is essential.
• Immunohistochemical stains are highly effective in distinguishing these entities.
• Timely and accurate diagnosis impacts patient prognosis and treatment.