Impact of a Modified HistoGel Method for Processing Endocervical Curettage Specimens on Diagnostic Yield

Endocervical curettage for diagnosing high-grade squamous intraepithelial lesions or worse in women with type 3 transformation zone lesions: a retrospective, observational study

BACKGROUND

This study aimed to assess the value of endocervical curettage (ECC) in detecting high-grade squamous intraepithelial lesion or worse (HSIL+) in women with type 3 transformation zone (TZ3) lesions, and to identify the clinical characteristics of patients with TZ3 lesions who benefit most from ECC.

METHODS

This retrospective, multicenter study included 1,905 women with TZ3 lesions who attended cervical screening in one of seven tertiary hospitals in China between January 2020 and November 2021. All participants had received abnormal results and had been referred to colposcopy. Risk factors were identified through univariate and multifactorial logistic analyses.

RESULTS

In total, 20.5% (n = 391) of HSIL+ cases with TZ3 lesions had been diagnosed with biopsy and ECC. ECC detected 0.8% (n = 15) HSIL+ cases otherwise missed by biopsy alone. Multivariate analysis identified four factors which influenced detection performance. The probability of detecting HSIL+ with ECC is 2.653 (95% confidence interval [CI] 1.009-6.977) times greater in women aged 40-49 years and 2.545 (95% CI 0.965-6.716) times greater for those aged 50 years and older compared to those younger than 30 years. The probability of ASC-H (atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion) and HSIL cytologies were respectively 2.415 (95% CI 1.213-4.808) and 2.933 (95% CI 1.648-5.220) times higher than for NILM (negative for intraepithelial lesion or malignancy). Women with human papillomavirus 16/18 infections were 2.299 (95% CI 0.942-5.613) times more likely to be HSIL+. Precancerous lesions were 35.884 (95% CI 12.214-105.426) times more likely in women who had high-grade colposcopic impressions compared to those with normal impressions.

CONCLUSIONS

ECC should be performed for patients with ASC-H or HSIL cytologies, human papillomavirus 16/18 infections, and for those with high-grade colposcopic impressions. This will increase the number of HSIL+ cases identified using biopsy by reducing the number of false negatives.

Adequacy in Endocervical Curettage

OBJECTIVES

Specimen adequacy is an important quality assurance component of a cervical Papanicolaou test. Although consensus exists on minimal acceptable cellularity for cervical Papanicolaou tests, no such criteria exist for endocervical curettage (ECC) specimens. We sought to identify minimum acceptable cellularity for accurate diagnosis of high-grade dysplasia (HGD) on ECC.

METHODS

All patients with HGD diagnosed in a loop electrosurgical excision procedure (LEEP) from May 8, 2018, to December 18, 2019, and an ECC in the preceding 6 months at our institution were included (n = 51). All ECCs performed before the LEEP were evaluated for cellularity of squamous cells using Aperio eSlide Manager (Leica Biosystems). Biopsy results concurrent with the ECC were noted. We compared the number of squamous cells in positive and negative ECC specimens using a t-test. The proportion of ECC specimens and concurrent biopsies undergoing immunohistochemical (IHC) staining for p16 were compared using the χ2 test. P < .05 was considered significant.

RESULTS

Endocervical curettage specimens positive for HGD have increased cellularity compared with negative ECC specimens (mean cellularity, 10,165 vs 1,055; P < .05). Further, IHC staining for p16 was more likely to be performed on an ECC specimen positive for HGD than on a negative ECC specimen (50% vs 3%; P < .05). Biopsies performed concurrently with a negative ECC finding were more likely to undergo p16 IHC than biopsies performed concurrently with a positive ECC finding (51% vs 7%; P < .05). Finally, we observed no difference in the proportion of biopsies undergoing IHC staining for p16 when comparing biopsies positive for HGD with negative biopsies (37% vs 46%; P = .33).

CONCLUSIONS

We find cellularity of approximately 10,000 cells adequate to diagnose HGD in an ECC specimen and cellularity of approximately 1,000 cells to be inadequate. Further, we find p16 IHC commonly used as a "rule-in" test on ECC specimens at our institution. Biopsies accompanying an ECC specimen negative for HGD are more likely to undergo p16 IHC than those accompanying an ECC specimen positive for HGD, but there is no difference in the proportion of biopsies undergoing p16 IHC when comparing positive and negative results in the biopsies themselves. These findings further support the need for adequate cellularity for diagnosis in ECC, especially when a biopsy is technically difficult. Further areas for exploration include investigating laboratory procedures to maximize the cellularity of ECC specimens.