Pagetoid dyskeratosis is a frequent incidental finding in hemorrhoidal disease.

Abstract

Pagetoid dyskeratosis is considered a selective keratinocytic response in which a small part of the normal population of keratinocytes is induced to proliferate. Pagetoid dyskeratosis has been found incidentally in the squamous epithelium of the skin in various locations and in the ectocervix in uterine prolapse. In cases in which these pale cells are conspicuous, there is a hazard of overdiagnosis. It has been suggested that friction is the most probable inductor of the lesion. To the best of our knowledge, pagetoid cells have not been reported in surgically resected hemorrhoids. We here describe the location of pagetoid dyskeratosis in the squamous epithelium of hemorrhoids and the incidence of this lesion in a group of 100 unselected patients surgically treated for hemorrhoidal disease. In addition to the conventional histologic method, special staining procedures and an immunohistochemical study of cytokeratins were performed in selected cases. Pagetoid dyskeratosis was found in 68 cases (68%) and was a prominent finding in 22 cases (22%). The cells of pagetoid dyskeratosis were strongly positive for high-molecular weight cytokeratin. These cells showed an immunohistochemical profile that was different from that of the surrounding squamous cells and indicative of premature keratinization. In hemorrhoidal disease, the cushions are susceptible to trauma as a result of prolapse. In this setting, friction may be the stimulus for the appearance of pagetoid dyskeratotic cells. These cells must be distinguished from the artifactual clear cells of the squamous epithelium, glycogen-rich cells, and koilocytes. The lesion must also be distinguished from extramammary Paget disease, pagetoid spread of carcinoma cells, pagetoid Bowen disease, and pagetoid melanoma. Pathologists should be familiar with the histologic features of pagetoid dyskeratosis in hemorrhoidectomy specimens to avoid misdiagnosis. Routine histologic study is usually adequate for recognizing this lesion.