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October 2005
Editors:
Michael Cibull, MD
Subodh Lele, MD
Melissa Kesler, MD
Lack of adherence to practice guidelines for women with atypical glandular cells on cervical cytology
Little or no residual prostate cancer at radical prostatectomy: vanishing cancer or switched specimen?
Significance of field validation in the CAP Interlaboratory Comparison Program in Cervicovaginal Cytology
Patient safety in anatomic pathology: measuring discrepancy frequencies
and causes
Lack of adherence to practice guidelines for women
with atypical glandular cells on cervical cytology
The authors conducted a study to estimate the rates and types of evaluation
of women with atypical glandular cells of undetermined significance on cervical
cytology and to assess these findings on the basis of published management guidelines.
The rates of histologic sampling, comprehensive initial evaluations, and secondary
evaluations were assessed in 477 women with an atypical glandular cells of undetermined
significance (AGC-US) Pap test from 1998 to 2001. A comprehensive evaluation
was defined as a colposcopy and an endocervical curettage with or without a
cervical biopsy. For women aged 35 or older, a comprehensive evaluation also
included an endometrial biopsy. A secondary evaluation consisted of a diagnostic
cone biopsy. Sixty-four percent of women with an AGC-US Pap test had histologic
sampling; 36 percent were followed by repeat Pap test only. Thirty-six percent
of women with an AGC-US Pap test had a comprehensive evaluation. Women with
an AGC-US Pap test that was subclassified as malignant appearing had higher
rates of histologic and comprehensive evaluations than women with a benign-appearing
or unspecified AGC-US Pap test (P<.01). Twenty-eight percent of women aged
35 or older had comprehensive evaluations compared with 57 percent of women
younger than the age of 35 (P<.01). Secondary evaluations were performed
in eight percent of women with persistent AGC-US Pap tests and two percent of
women with malignant-appearing AGC-US Pap tests after negative initial histologic
evaluations. Twelve of the 42 cases of disease (29 percent) were diagnosed more
than one year after the initial AGC-US Pap test. The authors concluded that
on the basis of accepted management guidelines, these data suggest that women
with AGC-US Pap tests are undermanaged in their initial and secondary evaluations.
Sharpless KE, Schnatz PF, Mandavilli S, et al. Lack of adherence to practice
guidelines for women with atypical glandular cells on cervical cytology. Obstet
Gynecol. 2005; 105(3): 501–506.
Reprint information not available.
Little or no residual prostate cancer at radical prostatectomy:
vanishing cancer or switched specimen?
With more vigilant screening for prostate cancer, there has been an associated
increase in patients with little or no residual cancer at radical prostatectomy
after an initial diagnosis of minute cancer on needle biopsy. This raises a
critical question as to whether the biopsy and subsequent radical prostatectomy
are from the same patient. The authors used PCR-based microsatellite marker
analysis to perform identity tests in 46 men (35 with minute cancer and 11 with
no residual cancer). Of the tests, 41 were interpretable, including 31 with
minute cancer and 10 with no residual cancer. All 31 interpretable cases with
minute cancer showed a match between the initial biopsy and radical prostatectomy
specimens. Nine of the 10 interpretable cases with no residual cancer showed
a match and one showed a mismatch. The remaining five cases (four with minute
cancer and one with no residual cancer) were considered uninterpretable due
to technical problems. The initial biopsy of the mismatched case had high-grade
cancer (Gleason score, 4+4=8) measuring 9.6 mm in length with perineural invasion.
The authors’ results confirm that most cases of “vanishing cancer”
in radical prostatectomy specimens reflect a chance sampling of a minute cancer
and not a switch in specimens. However, specimen switch, though rare, can occur,
and if there is high-grade or a lot of cancer on the biopsy but no cancer or
very minimal cancer in the radical prostatectomy specimen, one should verify
patient identity.
Cao D, Hafez M, Berg K, et al. Little or no residual prostate cancer at radical
prostatectomy: vanishing cancer or switched specimen? A microsatellite analysis
of specimen identity. Am J Surg Pathol. 2005;29:467–473.
Reprints: Dr. Jonathan I. Epstein, Dept. of Pathology, Johns Hopkins Hospital,
401 N. Broadway, Weinberg 2242, Baltimore, MD 21231; jepstein@jhmi.edu
Significance of field validation in the CAP Interlaboratory
Comparison Program in Cervicovaginal Cytology
In gynecologic cytology, expert opinion is often used as a gold standard for
evaluating new technologies, assessing legal matters, and validating cases for
use in educational programs and proficiency testing. However, the reliability
of expert opinion alone in selecting slides of a specific cytodiagnosis that
can be reproducibly and reliably identified by subsequent reviewers has not
been determined. The authors conducted a study to assess the ability of expert
opinion to select slides that are validated in subsequent reviews. In the College
of American Pathologists Interlaboratory Comparison Program in Cervicovaginal
Cytology, each case in every cytodiagnostic category is accepted for circulation
only after review by three expert cytopathologists. The percentage of these
cases that could not be reliably and reproducibly identified by program participants
for each cytodiagnostic category (“Failed field validation”) was
determined during the duration of the program from 1989 to 2004. More than 10,000
conventional smears and ThinPrep cases were selected by the expert panel for
circulation. Of these slides, 19 percent of conventional smears and 15 percent
of ThinPrep specimens failed field validation. Compared with overall slide performance,
significantly higher percentages (P<.001) of conventional smears with reference
diagnoses of unsatisfactory (51.7 percent), repair (58 percent), or low-grade
intraepithelial lesion (31.8 percent) and of ThinPrep specimens with reference
diagnoses of unsatisfactory (54.5 percent) and repair (76.9 percent) failed
field validation. In contrast, significantly lower percentages of conventional
smears with reference diagnoses of squamous cell carcinoma (4.5 percent), high-grade
squamous intraepithelial lesion (nine percent), Trichomonas vaginalis infection
(11.7 percent), or herpes (9.9 percent), and of ThinPrep specimens with reference
diagnoses of adenocarcinoma (5.1 percent), herpes (2.1 percent), and fungal
organism consistent with Candida (8.4 percent) failed field validation (P<.001
for all). The authors concluded that between 15 percent and 19 percent of gynecologic
cytologic cases that have been selected by expert cytopathologists as good examples
of cytodiagnostic abnormalities fail field validation. The proportion of cases
failing field validation varies with cytodiagnostic category, but it occurs
in all cytodiagnostic entities.
Renshaw AA, Wang E, Mody DR, et al. Measuring the significance of field validation
in the College of American Pathologists Interlaboratory Comparison Program in
Cervicovaginal Cytology: How good are the experts? Arch Pathol Lab Med. 2005;
129(5): 609–613.
Reprints: Dr. Terence J. Colgan, Suite 600, Pathology & Laboratory Medicine,
Mount Sinai Hospital, 600 University Ave., Toronto, Ontario, Canada M5G 1X5;
tcolgan@ mtsinai.on.ca
Patient safety in anatomic pathology: measuring discrepancy
frequencies and causes
The College of American Pathologists conducted a study to determine the frequency
of anatomic pathology discrepancies and the causes of these discrepancies. Seventy-four
participants in the CAP’s Q-Probes program self-reported the number of
anatomic pathology discrepancies in their laboratories by prospectively performing
secondary review (post-sign-out) of 100 surgical pathology or cytology specimens.
Reasons for the secondary review included conferences, external review, internal
quality assurance policy, and physician request. The frequency of anatomic pathology
discrepancy; type of discrepancy—that is, change in margin status, change
in diagnosis, change in patient information, or typographic error; effect of
discrepancy on patient outcome—that is, no harm, near miss, or harm; and
clarity of report were evaluated. The mean and median laboratory discrepancy
frequencies were 6.7 percent and 5.1 percent, respectively. Forty-eight percent
of all discrepancies were due to a change within the same category of interpretation—for
example, one tumor type was changed to another tumor type. Twenty-one percent
of all discrepancies were due to change across categories of interpretation—for
example, a benign diagnosis was changed to a malignant diagnosis. Although the
majority of discrepancies did not affect patient care, 5.3 percent had a moderate
or marked effect on patient care. The authors concluded that this study establishes
a mean multi-institutional discrepancy frequency (related to secondary review)
of 6.7 percent.
Raab SS, Nakhleh RE, Ruby SG. Patient safety in anatomic pathology: measuring
discrepancy frequencies and causes. Arch Pathol Lab Med. 2005;129:459–466.
Reprints: Dr. Stephen S. Raab, Dept. of Pathology, University of Pittsburgh,
UPMC Shadyside Hospital, 5150 Centre Ave., Pittsburgh, PA 15232; raabss@msx.upmc.edu
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