Endocervical glandular lesions exhibiting gastric differentiation: an emerging spectrum of benign, premalignant, and malignant lesions.

A variety of benign and malignant endocervical glandular lesions exhibiting gastric differentiation has been described in the past decade that has resulted in the concept of an important category of cervical adenocarcinoma which is unrelated to human papillomavirus (HPV). Both minimal deviation adenocarcinoma (MDA), also known as adenoma malignum, and the benign lesion lobular endocervical glandular hyperplasia (LEGH), have been known for some time to exhibit a gastric phenotype and immunophenotype (HIK1083 and/or MUC6 positive). Accumulated evidence suggests that a subset of LEGH (atypical LEGH) exhibits a degree of cytologic and/or architectural atypia which, in some cases, may be associated with and be a precursor of adenocarcinomas exhibiting gastric differentiation, including MDA. Gastric-type adenocarcinoma (GAS), a recently described subtype of cervical adenocarcinoma, is an emerging clinicopathologic entity. These neoplasms exhibit a spectrum of differentiation, including MDA as its very well-differentiated form, are unrelated to HPV, and exhibit aggressive clinical behavior. It is proposed that a LEGH-GAS sequence exists and, from a practical point of view, the development of optimal biomarkers is awaited to assist in early detection of GAS and atypical LEGH, as current HPV-targeted screening generally does not detect these lesions and strategies employing HPV vaccination will not prevent their occurrence. Pathologists should be familiar with the morphologic spectrum of these benign, premalignant, and malignant cervical glandular lesions exhibiting gastric differentiation. They are occasionally associated with Peutz-Jeghers syndrome or are a component of "synchronous mucinous metaplasia and neoplasia of the female genital tract."