Gastric‐type endocervical glandular neoplasms associated with aberrant p16 expression and K‐RAS gene mutation in Peutz‐Jeghers syndrome

In this report, unique endocervical glandular lesions exhibiting gastric differentiation were examined in a patient with Peutz‐Jeghers syndrome. The result of the human papillomavirus (HPV) in situ hybridization (ISH) for the hysterectomy specimens was negative, but they demonstrated a papillary mucinous adenocarcinoma at the proximal endocervix continuous to atypical lobular endocervical glandular hyperplasia. Both contained MUC6‐positive neutral mucin in cytoplasm, and showed different immunoreactivity to p16, Ki‐67, and p53. Moreover, they harbored the identical K‐RAS gene mutation suggesting that there was a common origin. Somatic K‐RAS mutation and defective function of p16 may have been involved in the tumorigenesis of these unusual mucinous neoplasms.