Gastric-type adenocarcinoma in situ of uterine cervix: cytological and histopathological features of two cases.

Benign, premalignant, and malignant endocervical glandular lesions occasionally show a gastric phenotype. We report 2 cases of gastric-type adenocarcinoma in situ (AIS) of the endocervix, not associated with lobular endocervical glandular hyperplasia or gastric-type adenocarcinoma. Cytologically, both showed endocervical glands with slightly enlarged nuclei, distinctive nucleoli, pseudostratified strips, and intracytoplasmic golden yellow mucin. Histologically, both lesions were situated in preexisting endocervical glands and presented columnar cells with voluminous pale eosinophilic cytoplasm and evident nuclear atypia. In case 1, the lesion was located at the mid-zone of the endocervical canal and, in case 2, at the outer endocervical canal with extension to the transformation zone and prominent intestinal metaplasia. In both, the cells showed voluminous cytoplasm containing gastric-type mucin, stained red by combined alcian blue/periodic acid-Schiff stain. Immunohistochemically, both lesions were positive for HIK1083 and p53, while negative for p16 and ER. Human papilloma virus (HPV) DNA was not detected by polymerase chain reaction. Our cases illustrate that gastric-type AIS can occur without lobular endocervical glandular hyperplasia. The lesions can occur in the outer cervical canal and present extensive intestinal differentiation. Awareness of this rare type of endocervical glandular lesion is important since they are pathogenetically different from the more common HPV-associated lesions and may become more prevalent in the HPV-eradicating era.