Cytologic and cytochemical features of adenoma malignum of the uterine cervix

BACKGROUND We previously reported that adenoma malignum (the mucinous type of minimal deviation adenocarcinoma [mucinous MDA]) of the uterine cervix expresses gastric phenotypes. The application of immunocytochemistry using HIK1083, a monoclonal antibody for gastric gland mucous cell mucin, enabled us to identify cellular clusters derived not only from typical lesions of mucinous MDA and less well differentiated lesions but also from gastric metaplasia. In this study, we tried to clarify the cellular features of such clusters in cervical and endometrial smears. METHODS Twelve cases of mucinous MDA were studied. Papanicolaou stain and immunostaining with HIK1083 were performed on histologic and cytologic slides, including cervical and endometrial smears, decolorized smear slides, imprint slides of the tumors, and imprint slides of normal endocervical and gastric mucosa. RESULTS Cellular clusters derived from metaplastic lesions, typical lesions, and less well differentiated lesions were found in 9, 4, and 2 cases, respectively. The cellular clusters derived from the metaplastic lesions lacked atypia but resembled those from gastric mucosa. Those derived from the typical lesions showed slight atypia. The cytoplasmic mucins of these cellular clusters, which were positive for HIK1083, were stained yellowish‐orange by Papanicolaou stain, whereas those of normal endocervical cells were negative for HIK1083 and were stained pinkish by Papanicolaou stain. CONCLUSIONS Yellowish‐orange staining of cytoplasmic mucins by the Papanicolaou method is an important diagnostic clue aiding identification of mucinous MDA and related lesions by cytology. Moreover, immunostaining with HIK1083 is a useful tool in the diagnosis of these lesions by cytology as well as by histology. Cancer (Cancer Cytopathol) 1999;87:245–53. © 1999 American Cancer Society. Yellowish‐orange staining of cytoplasmic mucins by the Papanicolaou stain and immunoreactivity for HIK1083 are important diagnostic clues aiding identification of adenoma malignum and related lesions by cytology.