BREAST CYTOPATHOLOGY

2 1. Introduction and Technical Aspects
term cytologic atypia in benign breast conditions (the socalled
gray zone diagnosis), which then requires tissue biopsy,
and lack of understanding of the inherent limitations of the
procedure by both clinicians and pathologists (such as inability
to reliably distinguish in situ from invasive carcinoma).
The performance and interpretation of breast FNA require
adequate training and experience. Correlation with subsequent
biopsies and clinical follow-up is mandatory in order
to improve the diagnostic yield and accuracy of the procedure.
Gray zone diagnoses as reported in the literature have
ranged from 1% to 22%, with an average of 10% in most
studies. Every effort should be made to minimize theses atypical/indeterminate
cytologic diagnoses. However, the “gray
zone” may also be the “comfort zone” for the cytopathologist,
and inexperience or lack of confidence on the part of the
cytopathologist may result in an increase in indeterminate
diagnoses.
Overall, breast FNA is enormously successful, with an
overall diagnostic sensitivity ranging from 80% to 100%, with
specificity over 99%. In the modern era, breast FNA has been
confronted with new roles and challenges. It is now routinely
expected that breast FNA will provide an accurate diagnosis,
analyze the biologic behavior of the tumor, supply biomarker
information such as estrogen/progesterone receptor status,
comment on cell proliferation index, and determine prognostic
indicators such as Her2neu expression. These expectations
can only be met if an adequate sample is obtained and the
pathologist is on site to triage the material for processing.
As in other areas of diagnostic anatomic pathology, breast
cytopathology has become a target for litigation. Review of
the literature clearly shows that, after gynecologic cytopathology
(Pap smears), breast FNA is the most common area
involved in lawsuits. The most frequent problem leading to
lawsuits has been overdiagnosis or false-positive diagnosis.
Recently, more and more cases of underdiagnosis or falsenegative
reports have led to litigation partly because advancements
in treatment protocols for breast cancer demonstrate
that higher survival rates closely parallel early diagnosis; even
short delays in diagnosis can affect prognosis. In a recent