Cytology and histology of endocervical glandular lesions: a review with emphasis on recent developments

In recent years, there has been vast change in the field of cervical pathology, most notably in the classification and approach to cervical glandular lesions. The publication of the 5th edition of the World Health Organization Classification of Tumours of Female Reproductive Organs in 2020 signalled a paradigm shift away from morphology-based categorisation towards an aetiology-based system linked to lesional human papilloma virus (HPV) status. This includes several newly described entities such as HPV-associated micropapillary and stratified mucin-producing carcinomas, and gastric-type adenocarcinoma in situ and atypical lobular endocervical glandular hyperplasia, both regarded as precursors to HPV-independent carcinoma of gastric type. Simultaneously, cervical screening programs in resource-rich nations have undergone major renewal, with transition to more sensitive primary HPV-based molecular screening. Diagnostic methods have also been expanded in recent years, including the availability of sensitive, immunohistochemically based in situ hybridisation testing for HPV on tissue samples. The rate of change has been rapid, exposing pathologists to potential knowledge gaps. In this review, many of the key changes pertinent to reporting these lesions are addressed.