Clinicocytopathological and immunohistochemical study of adenoma malignum of the uterine cervix.

Adenoma malignum is a rare type of very highly differentiated adenocarcinoma of the uterine cervix, and is quite difficult to diagnose because there are few findings definitely suggesting malignancy on cytologic or histologic examination. We recently encountered four patients with adenoma malignum and reviewed their clinicocytopathological and immunohistochemical findings. The most characteristic symptom was a watery discharge and an enlarged cervix was palpable, while multiple cystic lesions (MCL) were observed by transvaginal and abdominal ultrasonography, CT or MRI. On cytodiagnosis, the cervical gland cells formed large sheets or showed a palisading arrangement. Slightly enlarged nuclei and yellowish-orange staining of the cytoplasmic mucus were the characteristic findings. On histological examination, many cervical glands of different sizes were present and extended deep into the muscle layer, while branching or papillary growth into the lumen was also observed. On immunohistochemical study, HIK1083, a monoclonal antibody for gastric gland mucous cell mucin, was found to be positive in 3 of 4 cases, and this was fairly useful in the diagnosis of adenoma malignum.