Lobular endocervical glandular hyperplasia might become a precursor of adenocarcinoma with pyloric gland features.

We report a case of adenocarcinoma with pyloric gland features, which appears to have originated from lobular endocervical glandular hyperplasia (LEGH). Hematoxylin and eosin staining, as well as histochemical and immunohistochemical stainings were performed on formalin-fixed and paraffin-embedded specimens. LEGH was observed in the conization specimens. In the hysterectomy specimens, LEGH, atypical LEGH, and mucinous adenocarcinoma coexisted. The adenocarcinoma was located at a site distant from the transition zone. p16(INK4a) immunopositivity was extremely rare. Front formation was observed, and a transition from benign-looking columnar cells of LEGH to adenocarcinoma was recognized. These findings suggested that the adenocarcinoma with pyloric gland features arose from LEGH. LEGH is no longer regarded as a pseudoneoplastic lesion, and it is necessary to consider that LEGH is able to transform into a precursor lesion and to develop into an adenocarcinoma with pyloric gland features.