The objective of this study was to assess the prevalence of pathologically proven intrapulmonary lymph nodes and to evaluate their appearance on CT.
Prevalence of Pathologically Proven Intrapulmonary Lymph Nodes and Their Appearance on CT Mark S. Bankoff1 Niall J. McEniff1 Rafeeque A. Bhadelia Maria Garcia-Moliner2 Benedict
The objective
OBJECTIVE. proven
intrapulmonary
MATERIALS
1
underwent
D. T. Daly3
AND
Of
size,
position.
these
I 84
were
independently
diameter
he
study
logically
0361-803X/96/1 © American
Roentgen
AJR:167, September
1996
with
the
patients
7 to 1 2 mm.
had
were
periph-
lymph
solitary
All the nodes
of the nodules
evaluation any
existence
nodes.
Two
The
maxi-
nodules. were
located
been
previously
on CT have never series.
is to assess
the
with
well-circumscribed
and
evalu-
objective
prevalence
intrapulmonaiy
nodules
been
The
of
of patho-
lymph
nodes
peripheral
to
they
parenchymal
intrapulmonary
has
pulmonary
CT appearance,
(or multiple)
of
nodes
of CT-detected
specific
evaluate
their
located
within
in the lower
should
nodules.
3-mm
tional
Materials
were
1980
and
went
a minithoracotomy
uation
of peripheral
ered
1994. pulmonary
needle
aspiration
technically
patients
of
CT-guided
per-
had for
well-circumscribed
a known
was
inappropriate.
attempted.
nodules.
underfor eval-
abnornialities biopsy
difficult,
unsuccessfully 96
184
at our institution
In these patients.
cause.
investigated
in the study.
and Methods
Between
cutaneous
included
These
patients
underlying
Of
these
nodule
disease
two
thick
slices
to he resected a barium
were
was
marker
the
radiologists
no knowledge ules’
or
had
pleura
I 84
pleura
(such
those
found
in
obtained
through
the
localized
on full inspira-
placed
on the skin over
was
was performed to (Fig. I ). The barium marker was then replaced by an indelible skin marker. All nodules were successfully identified and excised during surgery. The resected nodules were itiimediately sent for pathologic analysis. All CT scans were reviewed independently by
consid-
peripheral were being
these
in the dii’-
nodules. The technique of minithoracotomy has been described in detail previously 131. Patients were positioned in the gantry of the CT scanner in the position selected for operative exposure. The
surface
nary abnormalities
entity, undergo
as primary tunior, infective process. collagen ascular disease) or for investigation of an abnormality seen on a chest radiograph. CT scans of the chest were obtained for each of these patients at I cm intervals with a I-cm slice thickness. Addi-
and a repeat
pulmo-
and
Although
particularly
20
lobes.
be considered
the nodule.
of peripheral
The lymph
well-circumscribed
intrapulmonary
conIirii
pulmonary Ray Society
to he
15 years for evaluation
patients.
673-629
from
Twelve
nodules.
intrapulmonary
tion,
been
AJR 1996:167:629-630
proven
appearance on CT. All patients who underwent minithoracotomy at our institution over the past
unknown 3Department ofThoracic Surgery, New England Medical Center, Tufts University School of Medicine, Boston, MA 02111.
varied
surface.
proven
pulmonary
2Department of Pathology, New England Medical Center, Tufts University School of Medicine, Boston, MA 02111.
the remaining
abnormal-
pulmonary
radiologists.
proven
documented [ 1 , 2]. However, to our the prevalence of these nodes and
in patients
Tufts University School of Medicine, Division of Computed Tomography, 750 Washington St., NEMC #180, Boston, MA 02111. Address correspondence to M. S. Bankoff.
by two experienced
nodules:
of single
in a consecutive
this
Center,
peripheral
pathologically
184 patients
pulmonary
nodules.
ated
New England Medical
all
pathologically
two
for
their appearance
of Radiology,
were
nodes do not possess
knowledge
1 Department
of
( 1980-1994),
peripheral
minithoracotomies
lymph
Roent-
period
of pathologically
on CT.
not a well-known of patients who
T
Presented at the annual meeting of the American gen Ray Society, San Diego, CA, May 1996.
a 15-year
in 17 ( 18%) of the 96 patients
ol’ the nodules
ferential diagnosis the lower lobes.
after revision
the prevalence appearance
the remaining nodules were located in the right middle lobe. CONCLUSION. Although intrapulmonary lymph nodes are our results indicate that they are discovered in a significant number lymph
26, 1995; accepted
their
well-circumscribed
assessed
pleural
to assess
of CT-detected
features
The nodules
of a visceral
had
radiographic
pulmonary nodules of the 17 patients had
Received December March 26, 1996.
96
was
Over
for evaluation
eral
mum
study
and to evaluate
METHODS.
patients,
and
RESULTS.
mm
nodes
minithoracotomies
ities.
nodes
of this
lymph
position.
were was
the nodule. presence
of
lung-nodule
scan
localization
experienced
in the
of the pathologic size.
number,
recorded. measured
field
findings. and distance
The from
distance the deepest
Each nodule was also evaluated calcification and for character
who
had
The nodfrom the from the aspect of for the of the
interface.
629
Bankoff
et al.
Fig. 1.-CT
scan through lower lobes of 58-year-old woman in right lateral decubitus position shows nodule to be resected (short arrow) that was localized on full inspiration. Note barium marker (long arrow) that was placed on skin over nodule for surface localization. Nodule in this patient measured 1.5 cm from adjacent pleural surface.
Fig.2.-Magnified
CT scan of right lower
lung in 69-year-old man in leftlateraldecubitus position shows intraparenchymal lymph node (straight arrow) in right middle lobe close to pleura. No distinct imaging features were recognized to permit diagnosis before surgery. However, note nonspecific peripheral opacity located posteriorly in right lower lobe (curved arrow) that was thought to be caused by scarring; its cause was not confirmed surgically.
Results Of guided
has been done using the
96
who
patients
for
minithoracotomies
of well-circumscribed nodules,
were
proven
lymph
nodes.
known
primary
of these
able occupational The patients
intrapulmonary
dominantly
I 7 patients
middle
distribution
Lymph
a
10 men and seven
The
with
a mean
of 8 mm.
lymph
nodes
were
found
lower
lobes.
Five
lymph
nodes
lower
lobe
and seven
predominantly
lobe. The remaining in the right middle
The in the
were
located
in the left
five patients had lobe. All nodules
the level of the carina.
We
no nodes in the upper lobes. All the were located within 20 mm of a vis-
ceral pleural
surface.
Distances
ranged
from
5
to 20 mm (mean, 1 1 mm) (Fig. 2). None of the lymph nodes was calcified. The lung-nodule interface
was usually
these features preoperative
were not helpful differentiation of
lymph
nodes
from
ondary) found
or inflammatory more frequently
among scribed
our
96
peripheral
smooth.
neoplastic
However,
in confident these benign
(primary
or see-
lesions, which were than lymph nodes
patients pulmonary
with
nodes
in the lung
lymph
nodes in the lower
half
of the lungs may be explained both by the larger
had two
15 had solitary in size from 4 to
diameter
is not clear.
well-circumnodules.
ventilation
and by the lymphatic
in the lower upper
lungs when
lungs
fluid production
compared
[1 1, 12]. The pathologic
all the specimens were reviewed. were anthracotic in cases. We
who
on
have also CT had
observed nodules
within
the
proved
to be intrapulmonary
adjacent
pulmonary
to a fissure.
in these patients a thoracotomy; not considered
with
the
analyses
of
The
nodes
patients deep
parenchyma lymph
middle
lymph
of
benign
nodes is still a pathologic
nodes
discovered
at
intrapulmonary
to
be
benign
diagnosis.
intrapulmonary
lobes
4.
How-
lymph
Ann
Thorac
C, Hamada
Yoshii
monary with
lymph
node
with
Gakkai
roe
Cardiovasc
lesion.
node Dis
1967;5
diagnosis
Dis
C/zest
9. Benisch
RL,
presenting
Spirn
PW,
f’/zest
multiple)
peripheral
630
lymph nodes [1, 2, no extensive study
larly
those
found
pulmonary
in the lower
nodules, lobes.
particu-
toplasmosis
the lung.
roentgen-
lymph
nodes.
lesion
of
Mark
and
El.
Intrapulmonary
1985;87:662-667 tumors.
In: Dail DH,
pat/wlog,
2nd
ed.
1994:1357-1359 M. Apical localization
tuberculosis, C/zest
A. An intrapulmoas a coin
1979;76:336-337
C/zest
nodes.
pulmonary
OF. The
B, Osborne
node
of benign intrapulmonary 4-10]. To our knowledge,
be
nodule.
1967:51:621-624
in the differential
(or
lymph
pulmonary
G. Gabriele
included
should
Intrapulmonary
intrapulmonary
B, Peison
10. Kradin
JG.
1:336-337 of
lymph
the lung.
i Tho-
BJ, Fred HL. Benign node presenting as coin
as a solitary
R. Wilson
ray
lymph
Weg
presenting Chest
nodule.
J 1974:67:1216-1218
Med
DS,
Shapiro
nary
Blumenthal lymph
South
7. Rosenthal
Kyobu
: I 17-122
1963;46:21-39
Surg
6. Blakely RW, intrapulmonary
in a patient
Nippon
5. Steele JD. The solitary pulmonary
aware of this diagnostic
ofsingle
nodules
pneumonia.
1993;31
Zasshi
Over the past 30 years, there have been many case reports and small series reported
which
of intra-
1991:51:465-469 et al. A case of intrapul-
silicotic
interstitial
idiopathic
S/zikkan
Surg
M, TaoY,
York: Springer-Verlag, 12. Goodwin RA, DesPrez
diagnosis
and
and in the right
pulmonary lymph nodes. Thorax 1964:19:44-50 3. Daly DBT. Faling U, Diehl JT, Bankoff MS. Gale ME. Computed tomography-guided minithoracotorny for the resection ofsmall peripheral pulmonary
I I . Dail DH. Uncommon mer SP, eds. Pulmonary
entity,
our
lobe.
nodes at percutaneous biopsy or at surgery. Therefore, it is important for radiologists to be
Discussion
in
case report.AiR 1969;l06:601-603 2. Trapnell DH. Recognition and incidence
8.
ever, with improvement in the image quality of Cr, more pulmonary nodules are likely to be identified and a higher proportion of these small peripherally placed nodules may ultimately be proven
nodules
pulmonary
are
of the periph-
I . Fellows KE Jr. Abell MR. Martel W. Intrapulmonary lymph node detected roentgenologically:
that
therefore, these nodes were in this study. Although at first
diagnosis
18%
that
nodes
References
appraisal these nodes appeared to be deep, they were in fact close to a pleural surface. The
for
in the lower
occurred
of the nodes
was generally
shown
patients who underwent minithoracotomies. The nodes were predominantly single
nodules.
several apparently
The nature
placed
has
lymph
for this
develop in response to antigenic stimuli, usually from inhaled dust. The predominant occurrence of intrapulmonary
ages of 63 and S I years,
below
study (10
[10]. The reason
12 mm,
found nodes
lobes and in the right
in the lower
lobe. In the only other sizable
study
accounting
erally
pre-
the level of the canna
the remaining nodes ranged
were located
nodule
patients), the lymph nodes were also seen below
of the 17 patients
Two
as a solitary
our
intrapulmonary
common,
had an identifi-
and The
lower nodes
had
nodes. of the intrapulmonaiy
occtared
nodes
In conclusion, benign
of them
nodules, nodules.
in the right
lymph
patho-
risk factor. were 30 to 70 years old, with
mean
proven
I 3 had a history
mean age of 57 years. had
the prey-
and
tumors None
CT to evaluate of pathologically
intrapulmonary lymph In our study, most
pulmonary to have
benign
Five
of smoking.
respectively.
found
and features
alence
CT-
the resection
peripheral
17 (18%)
logically
women
underwent
chronic
progressive
pulmonary
massive
fibrosis
HamNew
of hisof
1983:83:801-805
AJR:167, September
1996
