Microglandular hyperplasia – Although the architecture may be appear complex there is little atypia compared to high grade CGIN. The stratified appearance is due to basal cell hyperplasia. Mucinous glands are present on the luminal surface. Differential diagnoses include clear cell adenocarcinoma & endometrial adenocarcinoma with microglandular pattern.
Mesonephric duct remnants – Usually found deep in the endocervical wall. Small groups of glands and tubules lined by a single layer of columnar or cuboidal epithelium. The lumen contains homogenous eosinophilc material that is Pas and mucicarcmine positive.
Endocervical tunnel clusters – Benign pseudoneoplastic glandular proliferations. Type B are more expansile and lobular. Typically superficial on the inner endocervical wall. Absence of a infiltrative pattern, mitoses and malignant cytological features.
Deep Nabothian cysts – Mucin filled cysts with single layer of columnar or flattened endocervical cells.
Tubulo-endometrioid metaplasia – Lined by epithelium of tubal type with cilia and a terminal bar.
Transitional cell metaplasia – Appears transitional, umbrella cells may be present.
Robboy’s Pathology of the Female Reproductive Tract. 2nd Ed.