Microglandular hyperplasia consists of closely packed glands lined by low columnar or cuboidal cells with lumina containing mucin and inflammatory cells, particularly polymorphonuclear leukocytes.
Immunohistochemistry may be helpful in the differential diagnosis of usual-type endocervical adenocarcinoma and pseudoneoplastic glandular lesions, in particular with tunnel clusters and microglandular hyperplasia, as it may further help to characterize a particular lesion.
(29) Clear cell carcinoma must be distinguished from other tumorlike conditions containing clear cells such as (1) Arias-Stella reaction; (2) microglandular hyperplasia; and (3) mesonephric hyperplasia; as well as (4) carcinomas containing clear cells (squamous cell carcinoma and metastatic clear renal cell carcinoma).
(58,283) On the other hand, p53 immunoreactivity in microglandular hyperplasia ranges from negative to focally positive.
Several such entities are discussed in this review, including microglandular hyperplasia of the cervix mimicking well-differentiated endometrial and endocervical adenocarcinoma, reactive epithelial changes in the fallopian tubes mimicking adenocarcinoma or carcinoma in situ, atypical and hyperplastic changes in endometriosis, and pregnancy changes in the ovary including pregnancy luteoma and large solitary luteinized follicular cyst of pregnancy and puerperium.
Several entities have been recognized as mimics of malignancy; amongst those, microglandular hyperplasia probably represents the most prominent example.
(1) The term microglandular hyperplasia was first used by Kyriakos and coworkers (2) in 1968 for a cohort of patients taking oral contraceptives.
Microglandular hyperplasia is frequently an incidental finding but can present as a polyp or erosion.