Extramammary Paget’s Disease of Anal Canal Associated With Rectal Adenoma Without Invasive Carcinoma

Extramammary Paget's disease (EMPD) is a rare disease which is found in apocrine-rich locations such as anogenital region, axilla and rarely in other sites. Perianal EMPD is often reported as the involvement of perianal skin, but involvement of anal mucosa is very rare. Based on pathogenesis and association with either synchronous or metachronous malignancy, EMPD can be divided into primary and secondary types. Treatment approach for these two types of Paget's disease and their prognosis is different, thus it is important to make the distinction. Secondary type of Paget's disease is almost always described in association with invasive malignancy. While secondary Paget's disease arising in association with ductal carcinoma in situ of the breast is common, secondary EMPD associated with precursor lesion of the rectum without invasion is exceedingly rare. We report a very rare case of secondary Paget's disease of the anal canal in association with rectal tubular adenoma (precursor lesion) without malignancy.