EBC versus ECC

Q. What are the clinical differences between endocervical brush cytology and endocervical curettage, and how should the brushings be reported and billed?

Andrew H. Fischer, MD
Bill D. Tench, MD

A. The 2006 ASCCP consensus guidelines for managing women with abnormal cervical cancer screening tests¹ describe “endocervical sampling” as a “preferred” management when colposcopy is inadequate or colposcopic findings do not explain an abnormal Pap test result. An “inadequate” colposcopic examination means the entire transformation zone cannot be visualized, or any lesion cannot be seen in its entirety. The ASCCP guidelines do not distinguish between endocervical curettage (ECC) and endocervical brush cytology (EBC) for the endocervical sampling. There is growing evidence that EBC has advantages over ECC in terms of increased sensitivity for detection of lesions beyond colposcopic view, as well as higher adequacy rates.² An-other advantage is that EBC can be performed safely during pregnancy² while ECC is contraindicated.¹ Endocervical sampling is also sometimes used to assess completeness of excisional procedures, and EBC may be superior to ECC for this purpose.³ EBC has not apparently been evaluated for staging of endometrial can-cers (that is, detecting endocervical extension).

EBC may not have an advantage compared with ECC in terms of pain.⁴ Some studies identified a lower specificity of EBC compared with ECC (that is, false-positive detection of lesions in the endocervical canal), but subsequent work attributed these false-positives to inadvertent sampling of ectocervical lesions. Such ectocervical sampling has been shown to be prevented with the use of a sleeve during the brushing (see next paragraph). There is little data to support the use of ECC over EBC for evaluating women with atypical glandular cells. Since endocervical adenocarcinoma can be subtle in cytology samples, ECC may be preferable for managing Pap tests with atypical glandular cells. However, cell blocks are commonly performed on EBC specimens, and endocervical adenocarcinoma in situ is certainly detectable by EBC.⁵

EBC samples are typically obtained with a standard endocervical cytobrush. Ideally, the brush is covered with a sleeve (a spinal needle sheath) to help prevent inadvertent sampling of ectocervical lesions.⁶ The sleeve is apposed to the endocervical os and the brush is then extended 1–2 cm into the endocervical canal. The brush is rotated “180 degrees”⁷ or “five or six times”⁶ before being withdrawn. It seems possible that endocervical cells could be disrupted with too many rotations. The brush can be used to make a conventional smear, but liquid-based preparations perform at least as well as conventional smears⁸ and offer the potential to make a cell block. Recent studies with liquid-based preparations and cell blocks showed superior results for EBC compared with ECC.⁵

Adequacy criteria have not been well defined for either ECC or EBC. Ten endocervical cells may be a reasonable threshold for an adequate EBC specimen. Boardman, et al, defined an adequate EBC as five clusters of endocervical cells with at least 10 cells per cluster and an adequate ECC as one strip of endocervical epi-thelium with at least 10 cells.⁶ In their study, EBC (requiring 50 cells) was inadequate in two percent whereas ECC (requiring only 10 cells) was inadequate 20 percent of the time.⁶ Another investigation showed higher sensitivity with EBC than ECC with an adequacy threshold for either technique of any well-preserved endocervical cells.⁹ Since squamous cells are not a part of the target area, there is no apparent significance to the presence or absence of normal squamous cells. A typical report should attempt to grade any epithelial cell abnormality according to the Bethesda System. An explicit statement of adequacy is not necessary. A reasonable way to report the absence of an epithelial abnormality in an adequate EBC specimen would be: “Negative for malignant or dysplastic cells. Benign endocervical cells are present.” There is no defined role for HPV testing of EBC samples, and imaging systems are not used. All EBC samples are signed out by pathologists.

Though similar criteria are applied to interpreting EBC samples as Pap tests, the function of the EBC is different: If there is any abnormality detected in the EBC sample, it is by definition outside of colposcopic view, and a LEEP or a cone biopsy may be performed in some situations, per ASCCP guidelines. Pathologists need to be aware of the potential of an LSIL finding on EBC leading to a significant procedure, namely a LEEP or cone biopsy. Good communication with the gynecologist and review of previous Pap test findings that led to the EBC procedure are important for optimizing patient management.

Billing of EBC uses nongynecologic codes because the gyn codes were established specifically for CLIA-regulated Pap tests. 88112 is used for liquid-based preparations, and 88104 is used for direct smears. 88305 can also be used if a cell block is made.

References

Clarifying ‘test performed’

Q. In the CAP Laboratory Accreditation Program checklist question CYP.05300 (below), does “where the test was performed” refer to the location of the procedure? In our hospital, cytology specimens are obtained here but processed and stained at another CAP-accredited laboratory. Slides are returned, interpreted, and reported from here. Are we in compliance with the checklist requirement?

CYP.05300 Does the cytopathology report include all of the following required elements? 1) Name of patient and unique identifying number, if available; 2) Age and/or birth date of patient; 3) Date of collection; 4) Accession number; 5) Name of physician and/or clinic; 6) Name of the responsible reviewing pathologist, when applicable; 7) Name and address of the laboratory location where the test was performed; 8) Date of report; 9) Test performed; 10) Anatomic source and/or type of specimen; and 11) Basis for correction/amendment (if applicable).

Barbara A. Crothers, DO
Michael R. Henry, MD

A. The short answer is, yes, you are in compliance. In the recently published “Guidelines for the reporting of non-gynecologic cytopathology specimens” (Arch Pathol Lab Med. 2009;133:1743–1756), Crothers, et al, write that for cytopathology laboratory reports, “The header must include the full name and address of the laboratory where the test was performed....When processing is performed at one laboratory and interpretation or results are reported by another laboratory under a separate CLIA certificate, the names and addresses of both must be in the report. Laboratories may report this in different areas, as long as each laboratory is identified in the report.”

CLIA §493.1299 says, “The test report must indicate the following:...(2) The name and address of the labo-ratory location where the test was performed.” Further clarification in the Rules and Regulations by the Centers for Medicare and Medicaid Services dated Jan. 24, 2003, Federal Register vol. 68(16):3652, confirms the intent of the initial regulation: “It provides a contact for the individual who requested or is using the test results when additional information is needed for result interpretation and patient care.”

Thus, “test performed” would not apply to the procedure (where the specimen was procured) but to the location in which the test was analyzed or interpreted or both. This would seem to preclude processing of the specimen provided that no analysis or interpretation occurs. In the example given in the question on the preceding page, only the site viewing/reviewing and reporting the slides need have its lab’s name/address on the report, as long as cytotechnologists and pathologists are colocated at that originating site. A laboratory that only processes the slides need not have its name listed, as long as it is not issuing a report or portion of a report (such as initial slide assessment). As another example, site No. 1 may process Pap slides and the cytotechnologists on site may screen them, and then send them to site No. 2 for a pathologist’s interpretation. Slides certified only by the cytotechnologist would have only the first site’s name/address, but slides interpreted by the pathologist at site No. 2 would require both sites’ (Nos. 1 and 2) names/addresses on the report.

A similar situation can happen in surgical pathology. For instance, if surgical specimens are grossed at site No. 1, and sent to site No. 2 for embedding, cutting, staining, mounting, and coverslipping, then returned to site No. 1 for the pathologist’s interpretation, only site No. 1’s name and address need to be on the report, as no meaningful analysis or result has occurred at site No. 2. If, however, specimens were grossed and embedded, cut, stained, and mounted at site No. 1, then sent to site No. 2 for the pathologist’s interpretation, both sites’ names/addresses should be on the report, since macroscopic analysis (gross description) was performed at site No. 1.

Laboratories are free to format this information in whatever way they choose in the final report.