Diagnostic Cytology
Table 13.32 Comparison between Conventional Respiratory Cytology and Fine-Needle Aspiration (FNA) in Lung Cancer Diagnosis in 168 Patients
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insists on a complete series of at least three to five early morning
sputum samples and at least one bronchoscopy before resorting
to needle aspiration. An opposing group calls on accuracy, cost-
effectiveness, and rapidity of diagnosis of FNA as reasons for
advocating this procedure as the primary approach to suspected
lung cancer. A third group, to which our institution belongs,
takes an intermediate position in advocating a patient-by-patient
decision in the relative roles of these procedures. The few stud-
ies in the literature in which the more conventional methods
of diagnosis by sputum and bronchial material are compared
with FNA fail to clarify completely the controversy. Nasiell, in
a study of 42 patients with lung cancer, found that sputum and
bronchial material alone could have provided the diagnosis in
62% of the patients, whereas needle aspiration could have pro-
vided it in 76%.574 Dahlgren and Lind, in a similar study of 101
patients, recorded a 93% positive cancer diagnosis with needle
aspiration in contrast to a 42% diagnosis with only sputum.575
Landsman and his associates compared the diagnostic accuracy
of bronchial brushings and needle aspirates and found that
brushings detected 89% of lung cancers whereas aspirates
detected only 72%.576
Johnston reviewed a group of 168 consecutive lung cancer
patients in whom a definitive diagnosis of primary lung cancer
was established in a conventional cytologic specimen of spu-
tum or bronchial material or in a specimen obtained by FNA.577
This review's purpose was to compare the relative accuracies
between the modalities of sputum and bronchial material with
FNA in the diagnosis of lung cancer among these patients. The
patients included in this study were selected from a total of 1093
patients who had been diagnosed and treated for lung cancer at
our institution during a 5-year period.
In 325 of these patients (29.8%), a definitive cancer diagno-
sis was established from histopathologic material alone without
any cytologic diagnoses. In 420 patients (38.4%), both histo-
logic and cytologic material had been interpreted as being con-
clusively diagnostic for lung cancer. In 348 patients (31.8%), a
cytologic diagnosis of lung cancer was made without a histologic
confirmation. Thus, in a total of 768 of 1093 patients (70.3%), a
definitive cytologic diagnosis of cancer had been made. Of these
768 patients, a total of 168 (Table 13.32) patients had been
evaluated with both conventional respiratory cytologic methods
(sputum and bronchial material) and with FNA. In nine patient
(5.4%), only conventional respiratory cytologic specimens were
conclusively diagnostic for cancer. In 122 patients (72.6%), only
the FNA was diagnostic. In 37 patients (22.0%), both conven-
tional respiratory specimens and FNA yielded a definitive lung
cancer diagnosis. FNA was the only cytologic specimen positive
in 90.2% of large-cell undifferentiated carcinomas, 79.5% of
adenocarcinomas, 66.7% of small-cell undifferentiated carci-
nomas, and 58.2% of squamous cell carcinomas. In 26.5% of
patients, a diagnosis of cancer could have been established by
conventional cytologic specimens without the need for proceed-
ing to percutaneous FNA. From this study, it was concluded that
the techniques of conventional respiratory cytology and FNA are
complementary in the diagnosis of lung cancer. Although the
percentage of lung cancers diagnosed by FNA alone was much
greater than that by conventional respiratory cytology alone,
more than a fourth of these cancers could be detected by the less
invasive techniques of sputum sampling and bronchoscopy. In
a similar study, Fraire and associates reported positive predic-
tive values of cancer as 100% for sputum, 94.1% for brushings,
93.0% for washings, and 98.6% for FNA.578
Over the years of development of needle aspiration at our
institution, a formal protocol for its use has never been formu-
lated. Individualized physician decisions about the diagnostic
approaches to lung lesions have resulted in the data shown in
Table 13.29. Information such as this emphasizes the diagnostic
effectiveness of conventional respiratory cytologic methods. The
question then of whether FNA should be the primary diagnostic
tool becomes a complex one of balancing such considerations
as length of a patient's hospital stay, economic factors, reluc-
tance of some patients to permit their lungs to be pierced by
needles, and the morbidity of needle aspiration. In the experi-
ence of our laboratory, sputum and bronchial material provide
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