Thin-layer cytology findings of papillary adenosquamous carcinoma of the cervix. Report of a case with histologic correlation and molecular analysis

BACKGROUND: Papillary squamotransitional cell carcinoma of the lower female genital tract is a rare form of malignancy with distinctive histologic features. To my knowledge, its adenosquamous counterpart has not been reported before. CASE: A 69-year-old woman presented with postmenopausal bleeding due to a bulky cervical tumor. The thin-layer cytology preparation (Autocyte, TriPath Imaging, Burlington, North Carolina, U.S.A.) was of high cellularity and contained multiple small, papillary clusters of basaloid to columnar cells. Discernible fibrovascular cores were noted. In the background were many loosely dispersed, bland-looking columnar cells as well as cells of high grade squamous intraepithelial lesion (CIN 3). On a diligent search, scattered adenocarcinoma cells containing distinct intracytoplasmic vacuoles were found. There were a small number of dyskaryotic squamous cells with bizarre shapes, assuming "tadpolelike" morphology. Histologic examination of the tumor biopsy showed a papillary tumor with central fibrovascular cores covered with mitotically active, poorly differentiated squamous cells that imperceptibly merged with abortive glandular structures. Molecular analysis using the polymerase chain reaction and restriction fragment length polymorphism revealed the presence of human papillomavirus type 16 DNA in the liquid-based cytology sample. CONCLUSION: Papillary adenosquamous carcinoma of the cervix shares some morphologic and even histogenetic overlaps with papillary squamotransitional cell carcinoma and, to a lesser extent, conventional endocervical adenocarcinoma. It may pose certain diagnostic dilemmas for the unwary. In view of its distinctive cytohistologic features, this tumor warrants greater recognition in gynecologic pathology.