Presence of 10 transformation zone cells in endocervical curettage should not be required for adequacy

OBJECTIVES

In another publication, we concluded endocervical curettage (ECC) should have a minimum number of squamous cells for adequacy, similar to the requirements for adequate cervical Papanicolaou smears. Here, we investigate if also, similar to cervical Papanicolaou smears, the presence of at least 10 cells from the endocervical/transformation zone (EC/TZ) in ECCs should be used as a quality assurance measure or if, instead, at least 10 EC/TZ cells should be part of the adequacy criteria for ECC, with an emphasis on diagnosis of at least high-grade squamous dysplasia (HGD).

METHODS

All patients with at least HGD diagnosed on an excisional biopsy specimen (loop electrosurgical excision procedure [LEEP]) from May 1, 2018, to December 31, 2019, and an ECC in the preceding 6 months at our institution were included. Number of EC/TZ cells present in ECCs was counted visually and categorized as less than or greater than 10 TZ cells. A χ2 test was used to evaluate the proportion of ECCs with and without HGD and the presence or absence of at least 10 EC/TZ cells. Given our recent work encouraging at least 1000 squamous cells in an ECC to be considered adequate, we also evaluated only ECCs with greater than 1000 squamous cells with and without HGD and the presence or absence of at least 10 EC/TZ cells. P value was <.05.

RESULTS

Fifty-one LEEPs with HGD and a preceding ECC in the previous 6 months were identified. Of the 51 ECCs, 6 had fewer than 10 EC/TZ cells and 45 had at least 10 EC/TZ cells. A similar proportion of the ECCs with HGD had at least 10 EC/TZ cells as those without HGD (93% vs 86%, P = .53). Using only ECCs with greater than 1000 squamous cells, we still found no statistical difference in the proportion of ECCs with HGD having greater than 10 EC/TZ cells compared to those without HGD (91% vs 100%, P = .49).

CONCLUSIONS

We found that the presence of at least 10 EC/TZ cells does not increase the likelihood of finding HGD in an ECC performed in the 6 months prior to a LEEP with HGD. Similar to the use of the TZ component in cervical Papanicolaou smears, the presence or absence of at least 10 TZ cells in an ECC should only be considered a quality assurance measure and not be used as a criterion for adequacy of the specimen.

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.

Evaluation of Roche Hemolysis Index for Reporting of Plasma Hemoglobin, and Considerations Regarding Hemolysis Detection in Use of Ventricular-Assist Devices

Introduction/Objective

Our cardiac intensive care unit (CICU) asked the laboratory to provide plasma hemoglobin testing to monitor effects of ventricular-assist devices (VAD). Roche hemolysis index (HI) has been reported to be suitable for this purpose. Use of HI as a reportable test, however, must be validated in-house as a laboratory- developed test (LDT), according to CLIA regulations. We describe results of our evaluation, and caveats for intended use.

Methods/Case Report

Concentrated hemolysate was produced by osmotic lysis of packed red blood cells in water. Hemolysis in plasma was by dilution of concentrated hemolysate. Verification of HI as a measure of hemoglobin (mg/dL) used the Sigma-Aldrich spectrophotometric hemoglobin assay as a gold standard. Linearity, linear range, sensitivity, were investigated by dilution measurements; interferences by admixture experiments; reproducibility (precision, intra- and inter-assay) in each case by replicate measurements (n = 20).

Results (if a Case Study enter NA)

HI was confirmed to correspond to hemoglobin in mg/dL. Linearity was between 2-1000 mg/dL (r2 &gt;0.99). Intra-assay precisions were &lt;=2.5% (hemoglobin = 74,148 mg/dL); inter-assay precisions were &lt;=4.9% (hemoglobin = 69,139 mg/dL). HI variability was ±2 at very low values (0-10 mg/dL). There were no interferences observed among common therapeutic drugs. Hyperlipemia (evaluated up to lipemic index (LI) = 225) and hyperbilirubinemia (evaluated up to icteric index (II) = 7) demonstrated no significant interference.

Conclusion

Analytically, HI exhibited acceptable performance for reporting of plasma hemoglobin. Deployment would require establishment of quality control (QC) and proficiency testing procedures for HI. Clinically, a caveat for use is that HI cannot distinguish between hemolysis in circulation vs. that due to sample collection. For the CICU, HI &gt;10 mg/dL is characteristic of more than 20% of samples drawn in general, irrespective of use of VAD. Temporal patterns of HI must therefore be carefully evaluated in parallel with haptoglobin measurements to assist in VAD management.