Our purpose is to report a case of unexpected anal adenocarcinoma found in a hemorrhoidectomy specimen. A review of the literature, with emphasis on extramucosal anal adenocarcinoma as a pathologic entity, is included. Our patient presented with a 2-year history of grade III prolapsing internal hemorrhoids. A hemorrhoidectomy was performed and gross examination of the specimen was unremarkable. The pathologic evaluation revealed microinvasive well-differentiated adenocarcinoma at the squamocolumnar junction. There was neither an apparent connection with the overlying mucosa nor an in situ component. A metastatic workup ruled out any other site of malignancy. At follow-up 18 months after surgery, no evidence of malignancy or recurrence was observed. An unexpected extramucosal anal adenocarcinoma in a hemorrhoidectomy specimen is a very exceptional finding. Review of the literature does not support routine histopathological examination of hemorrhoidectomy specimens.