PRESACRAL EPIDERMAL CYST FOUND IN AN ADULT MALE WITH A HIGH CEA CONTENT - REPORT OF AN UNUSUAL CASE

A 63-year-old Japanese man presented with constipation, having noticed flat stools for several years. Digital examination of the rectum, fol lowed by barium enema, colono-fiberscopy, computed tomography (CT), an d magnetic resonance imaging (MRI) revealed an oval mass located betwe en the retrorectal and presacral space without any mucosal lesion. Thi s mass had narrowed the rectal lumen by compressing the rectum anterio rly. Although the plasma levels of the tumor markers were within the n ormal range, those of the tumor contents were elevated with a carcinoe mbryonic antigen (CEA) of 118 ng/mL, while the alpha-fetoprotein (AFP) value was 1 ng/mL. The tumor was completely extirpated through an abd ominal incision, and there has been no evidence of recurrence thus far . Histological examination showed that the tumor wall was made of kera tinized stratified squamous epithelium without any cutaneous adnexal s tructure, and hence it was diagnosed as an epidermal cyst. CEA was ide ntified in these benign epithelial cells by immunoperoxidase staining using a monoclonal antibody. To the best of our knowledge, there have been only four other cases with a presacral epidermal cyst documented in the Japanese literature, all of whom were female. Our patient is th e first reported case of an adult male with a presacral epidermal cyst .