The association of atypical squamous cells, cannot exclude a high grade squamous intraepithelial lesion, hyperchromatic crowded groups and high grade squamous intraepithelial lesions involving endocervical glands.

BACKGROUND

Hyperchromatic crowded groups (HCGs) are often classified as atypical squamous cells, cannot exclude a high grade squamous intraepithelial lesion (ASC-H) on ThinPrep Pap tests. This study reports on the association of HCG's with high grade squamous intraepithelial lesions (HSIL) involving endocervical glands.

METHODS

Over a 3-year period (January 1, 2018-December 31, 2020), 115 (0.2%) of 63,817 Pap tests were diagnosed as ASC-H. Histologic follow-up was available in 76 (66%) cases; 42 (55%) cervical biopsies; and 34 (45%) cervical cones/LEEPs.

RESULTS

Based on the histologic results, 49 ASC-H cases showed HSIL/CIN 3 and form the basis of this study. ThinPrep Pap tests showed two cell patterns; atypical immature squamous metaplastic cells and HCGs, each of which was difficult to distinguish from HSIL. On histologic correlation all 10 ASC-H Pap Tests with individual atypical immature squamous metaplastic cells showed HSIL/CIN 3 without endocervical gland involvement and 37 (95%) of the 39 Pap Tests with HCGs showed HSIL/CIN 3 with endocervical gland involvement.

CONCLUSION

The results of this study support the premise that a subset of HCGs represent endocervical gland involvement by HSIL as opposed to a glandular lesion; in particular endocervical adenocarcinoma in-situ.