What the 2002 nongynecologic cytology data tell us
David C. Wilbur, MD
Each year the data from the nongynecologic cytology survey are compiled and analyzed
for overall trends and changes from prior years. This databank is a valuable
resource that can be used to identify areas of cytology where interpretational
difficulties may arise, and in which improvement via education can be targeted.
In the 2002 databank, responses
from 1,311 laboratories were included, constituting the interpretations of
3,145 pathologists and 2,546 cytotechnologists. However, only laboratory responses
are considered in the tabulations because this represents the closest simulation
of actual practice. Generally, statistics for a given interpretational category
are considered for the summary when there are more than 100 responses for
In the 2002 database, we
noted a slight improvement in accuracy of interpretation as compared with
data from 2001. It is unknown at this time whether this performance is due
to better participant performance or to the inclusion of better (more representative)
slide challenges in the program.
Several interesting highlights
from the data follow:
Effusion specimens showed significant false-positive results when chemotherapy
or radiotherapy effect were present (21 percent pleural, five percent ascitic).
Squamous cell carcinoma in effusion specimens continues to be difficult for
participants, with 23 percent of such cases being false-negative in pleural
fluids and 31 percent false-negative in ascitic fluids. (Readers are referred
to a discussion addressing this at www.cap.org
under Cytopathology Unknown Cases.)
Specimens showing benign chronic inflammation prompted false-positive/suspicious
interpretations in 26 percent of responses. (Flow cytometric information would
be most useful in this differential, and the CAP is exploring the possibility
of adding this information to the challenges.)
Pulmonary hamartomas show a 25 percent false-positive/suspicious rate on FNA.
Cases of lobular carcinoma are difficult to identify (10 percent false-negative
rate) and classify (nearly 50 percent called of ductal origin) on FNA specimens.
This area remains one of the most difficult FNA interpretations for participants.
Pleomorphic adenomas and Warthin’s tumors both showed a seven percent
false-positive/suspicious rate. Acinic cell carcinomas and adenoid cystic
carcinomas showed high false-negative rates (35 percent and 39 percent, respectively).
Benign urines with instrumentation effect showed false-positive/suspicious
rates of 12 percent.
Reactive lymph nodes showed a 16 percent false-positive/suspicious rate in
FNA specimens. (As for CSF, the addition of flow cytometric information may
be helpful to participants.)
For further observations,
please review the 2002 year-end summary document that will be sent to participants
in the Interlaboratory Comparison Program in Nongynecologic Cytopathology.
Data such as these form the basis for several differential diagnostic data
and slide review projects now underway or recently completed by CAP Cytopathology
Committee members. Two articles were published on breast1 and normal
cellular elements in fine-needle aspiration specimens.2 An article
detailing effusion cytology data has been completed and submitted for publication,
and projects detailing salivary gland and thyroid data are in progress. The
data compiled in each area form fertile soil for discussions of differential
diagnosis. In addition, the data provide insights into the “standard”
for interpretation in each area. Such data can have broad utility from educational,
research, and medicolegal standpoints. Participants are encouraged to review
these data carefully. The committee members appreciate comments and observations.
- Young NA, Mody DR, Davey DD. Diagnosis and subclassification
of breast carcinoma by fine-needle aspiration biopsy: results of the Interlaboratory
Comparison Program in Non-gynecologic Cytopathology. Arch Pathol Lab
- Young NA, Mody DR, Davey DD. Misinterpretation of normal
cellular elements in fine-needle aspiration biopsy specimens: observations
from the College of American Pathologists Interlaboratory Comparison Program
in Non-gynecologic Cytopathology. Arch Pathol Lab Med. 2002;126:670–675.
Dr. Wilbur, chair of the Nongynecologic Working Group of
the CAPCytopathology Committee, is director of cytology at Massachusetts General