Q & A Feature
NGC Q & A
Q. What is the purpose of having
the HSIL/carcinoma, NOS diagnostic category in the response menu
of the Interlaboratory Comparison Program in Cervicovaginal Cytopathology?
A. The program added several diagnostic
categories in 2000. The category HSIL/carcinoma, NOS is used primarily
for educational slides illustrating high-grade processes and cancers
not easily classified by other menu options. Examples include Paps
that show features worrisome for an invasive process but that lack
all of the classic features such as diathesis and prominent nucleoli.
Other examples of HSIL/carcinoma, NOS cases are adenosquamous carcinomas
and poorly differentiated carcinomas. Participants can also use
this menu interpretation for cases in which they do not feel comfortable
distinguishing between HSIL and invasive carcinoma. This may be
a problem particularly for liquid-based Paps, in which diathesis
may be more difficult to detect.
While it may be tempting to use the HSIL/carcinoma, NOS category
as a “wastebasket” diagnosis to encompass all lesions
that appear to be high-grade, participants are still encouraged
to make a more specific diagnosis when possible. A participant response
of adenocarcinoma or squamous carcinoma in a case with a reference
diagnosis of HSIL would not be counted as a diagnostic error, because
these diagnoses fall within the same diagnostic category for grading
purposes. Thus there is no penalty for trying to distinguish between
HSIL, squamous carcinoma, and adenocarcinoma. By attempting to make
a specific diagnosis in most cases, participants can assess their
diagnostic skills and maximize the educational value of the program.
Jonathan H. Hughes, MD, PhD
Laboratory Medicine Consultants, Ltd.