Abstract
This is a case report of mucinous cancer of the anal canal invaded muscular layer, although it was 5 mm in diameter.
A 55-year-old woman was admitted to the hospital because of an anal tumor which was felt at defecation. There were previous histories of cancer of eterire cervix and thyroid cancer. The lesion was located in the middle of the anal canal. Transanal wide excision of the tumor under a suspicion of anal cancer revealed mucinous adenocarcinoma grown in the subepithelial layer with evident invasion to muscular layer. Abdominoperineal rectal amputation with lateral lymphadenectomy was performed and pathological examinations showed no remnant cancer cells in the local area and lymph nodes, either.
It is very hard to find early stage anal cancer originated from the anal canal gland. Furthermore, even a small lesion like in this case can have a high malignant potential. We should take the possibility of anal cancer into consideration at the time of examination of an anal tumor.
