College of American Pathologists



Reprinted from October 1996 CAP TODAY

Q: Do the Clinical Laboratory Improvement Amendments of 1988 mandate that all Pap smears classified as "cellular changes associated with inflammation" be reviewed by a pathologist?

A: CLIA ’88 mandates that pathologists review Pap smears with reactive or reparative changes.1 Because “cellular changes associated with inflammation” are reactive, I interpret the CLIA rule as requiring pathologist review.

Important practical problems are, however, associated with Bethesda System diagnoses of noninfection benign cellular changes. First is the threshold for interpreting features as BCC rather than as within normal limits. Wide variation can be found among cytologists and laboratories regarding this threshold, with some having very high rates of BCC and others very low, or even zero, rates; high rates would require the pathologist to review many negative cases, which may not be feasible.

Second, BCC can be an interpretive trap. A recent CAP Q-Probe about retrospective review of negative smears preceding diagnosis of high-grade intraepithelial lesion or carcinoma found that the earlier BCC smears were more likely to be false-negative than the earlier within normal limits/negative smears; three-fourths of the errors for within normal limits/negative cases were screening errors, but more than two-thirds of the BCC errors were interpretive.2 This finding gives support to the practice of rescreening or hierarchic review of cases screened as BCC, or both.

Third, some clinicians and pathologists perceive that BCC is an abnormal diagnosis that requires action. The effect can be unfortunate, causing women with no evidence of an epithelial cell abnormality to undergo unnecessary and distressing procedures. Two thoughtful editorials about this problem appeared in Diagnostic Cytopathology in 1994.3, 4

The undersigned author’s laboratory addresses the issue by not reporting noninfection BCC diagnoses. Cases in that category undergo pathologist review, and the pathologists revise some of the diagnoses to atypical cells of undetermined significance or worse. However, if the pathologist agrees that the changes do not represent an epithelial cell abnormality and thus require no clinical action, the diagnosis is within normal limits, and the interpretation of BCC is placed in the laboratory record but is not reported.

The current edition of the CAP Laboratory Accreditation Program cytopathology checklist requires pathologist review of cases showing repair, but not those with reactive changes; this practice was recommended by the CAP Cytopathology Committee. The LAP has deeming authority under CLIA’88 to accredit laboratories in cytopathology, and this checklist item has been approved by the Health Care Financing Administration.

For the aforementioned reasons, however, CAP-accredited laboratories may want to follow the CLIA final rule requirement for pathologist review of reactive changes or, altematively, may submit all or many BCC cases for cytotechnologist rescreening. The primary goal would be to identify those cases for which the diagnosis should be upgraded to an epithehal cell abnormality, with a secondary goal of downgrading BCC interpretations to “within normal limits” when appropriate.


1. United States Department of Health and Human Services, Clinical Laboratory Improvement Amendments of 1988 Final Rules. Federal Register. Feb. 28,1992.

2. Jones BA. Rescreening in gynecologic cytology: Rescreening of 3,762 previous cases for current high-grade squamous intraepithelial lesions and carcinoma--a College of American Pathologists Q-Probes study of 312 institutions. Arch Pathol Lab Med. 1995;119:1097-1103.

3. Luff RD. Benign cellular changes: Have we inadvertently reinvented the Class H cytology sign-out? Diagn Cytopathol. 1994;10:309-310.

4. Young NA, Kline TS. Benign cellular changes: Allied ambiguity in CLIA ‘88 and The Bethesda System. Diagn Cytopathol. 1994;10:307-308.

Mary Nielsen, MD
Pathology Consultants

Wichita, Kan.

Chair, CAP Cytopathology Committee