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.