Atypical glandular cells (AGC): Cytology of glandular lesions of the uterine cervix

Abstract

The Pap smear is a well-known screening tool for squamous lesions of the uterine cervix. However, its screening role in glandular lesions is less effective. The incidence of squamous cell carcinoma of the cervix has dramatically decreased with the advent of Pap smear and recent understanding related to HPV carcinogenesis of cervical cancers including the advent of HPV vaccines. However, in recent years, the incidence of glandular abnormalities, diagnosed on Pap smears, has increased with greater sensitivity and precision. The incidence of atypical glandular cells (AGC) is approximately 0.18–0.74% of all cervical smears with a reported prevalence of 2.5% among all Pap smears. A high degree of suspicion, good clinical history, and the presence of diagnostic cytomorphological findings are essential for the proper interpretation of glandular cell abnormalities. A methodical approach to evaluate Pap smear greatly helps interpretation and avoids the diagnostic pitfalls. The Bethesda System for reporting cervical cytology has categorized glandular cell abnormalities into various categories as follows: Endocervical adenocarcinoma in situ (AIS) Atypical glandular cells (AGCs) Endocervical cells: a1 NOS or specify in comments; a2 Favor neoplastic Endometrial cells: NOS or specify in comments Adenocarcinoma (AdCa) Endocervical Endometrial Extrauterine NOS Subtle differences in quantitative and qualitative cytologic features are essential for distinguishing one category from another. In this chapter, we highlight an organized approach for the interpretation of glandular abnormalities in Pap smear for our readers. This is an overview of the Bethesda categories, the reason for classification, and differential diagnosis with key characteristic features. An approach to the methodical evaluation of hyperchromatic crowded groups is discussed with key cytomorphologic differences. An algorithmic approach is suggested to facilitate the interpretation of various AGC categories.

Fine‐needle aspiration diagnosis of secondary malignant tumors of the thyroid gland: A single‐institution experience of 17 cases

“…In case 12 of adenocarcinoma from the esophagus, the arrangement of tumor cell fragments in the smear was very similar to that of PTC at low magnification, but the nuclei did not have typical PTC nuclear features. We observed that some of the tumor cells showed cytoplasmic mucusrich features under the microscope (Figure 3A), similar to the honeycomb appearance of the glandular epithelium of the cervical canal in cytological smears, 53 a cytological feature that has not been reported in PTC, which helps to suggest a nonthyroidal primary.…”

Clinicopathological features of atypical glandular cells, not otherwise specified, on cervicovaginal pap smears

“…The AGC‐NOS category includes AGCs with a morphology that is short of adenocarcinoma but overlaps with reactive endocervical/endometrial cells and cells with reparative changes 14 . The definitive interpretation of adenocarcinoma may also be hindered by quantitative and/or qualitative difficulties such as poor preservation and degenerative alterations.…”

Trouble-makers in cytologic interpretation of the uterine cervix

“…It is reported that the most common histologic diagnosis following cytologic diagnosis of AGC is SIL. Upon histologic correlation of AGC, about 15% have been reported to be associated with SIL, 1% with AIS, and 0.5% with adenocarcinoma [ 19 ]. This is attributed to the fact that it is most difficult to differentiate glandular abnormality from SIL with glandular involvement [ 20 ].…”

“…The most frequent and helpful cytological features of HSIL with glandular extension that are indicative of squamous origin are as follows: Syncytial clusters, sheets with loss of central polarity, oval nuclei, inconspicuous nucleoli, peripheral nuclear flattening, and nuclear grooves. The chromocenters in HSIL nuclei can often be misinterpreted as nucleoli, which may mislead to AGC [ 19 ]. The longitudinal axis of the peripheral nuclei are parallel to the long axis of the cellular cluster with one sided flattening ( Fig.…”