Pathologic features of anogenital precancerous high‐grade squamous intraepithelial lesion (squamous cell carcinoma in situ)

Abstract

Precancerous high-grade squamous intraepithelial lesion (HSIL), the current consensus terminology for anogenital squamous cell carcinoma in situ (SCCIS), often presents with distinctive histopathologic findings that may be a function of anatomic site or associated human papillomavirus infection. Fifty-six specimens of anogenital HSIL were compared with an equal number of specimens of SCCIS from non-anogenital sites in regard to the presence of parakeratosis, flag sign in the stratum corneum, compact stratum corneum, hypergranulosis, koilocytes, small blue cells, clonal populations of keratinocytes, pagetoid scatter of atypical keratinocytes, clear cell change, glassy red cytoplasm, pigmentation, nuclear/cytoplasmic(N/C) ratio >2/1, nuclear hyperchromasia, pleomorphic nuclei, mitotic figures, abnormal mitotic figures, dyskeratotic keratinocytes, involvement of skin appendages, acantholysis and amyloid deposition. Hypergranulosis, koilocytes, small blue cells, pigmentation, nuclear hyperchromasia, dyskeratotic keratinocytes and amyloid deposition were more frequently noted in anogenital HSIL. Parakeratosis, clear cell change, pleomorphic nuclei, skin appendages involvement and acantholysis were strongly associated with non-anogenital location. There was no significant difference in the incidence of the remaining features. The strongest predicators of an anogenital location included hypergranulosis, koilocytes, small blue cells and nuclear hyperchromasia. Pigmentation and amyloid deposition were also strongly associated with an anogenital location.