A Novel Ciliated, Mucin-producing Variant of HPV-related Cervical Adenosquamous Carcinoma In Situ: A Case Report.

Uterine cervical adenosquamous carcinoma in situ was originally defined as having either a uniform population of cells with features intermediate in appearance between glandular and squamous cells, or a mixture of distinct glandular and squamous components within a single lesion. The former type would likely be reclassified today as stratified mucin-producing intraepithelial lesion, while the latter type is vanishingly rare. Here, we report a novel case of bona fide adenosquamous carcinoma in situ, which exhibits 2 morphologically and immunophenotypically distinct components: (1) an inner glandular component composed of a single layer of p40-negative, ciliated, mucin-producing dysplastic columnar cells and (2) an outer p40-positive, stratified dysplastic squamous component otherwise identical to cervical intraepithelial neoplasia-3. Both components show block-positive staining for p16 and are positive for high-risk human papillomavirus RNA by in situ hybridization. Our finding expands the histological spectrum of human papillomavirus-associated preinvasive cervical lesions while also providing further evidence that human papillomavirus-driven processes can exhibit ciliated morphology.