malignant vs. benign pleural lesion: ct findings › synapse › data › pdfdata › 1016... ·...
TRANSCRIPT
大짧放射線뽑쩔會끓‘ 第 26 卷 第 4 號 pp. 735 -742. 1990 Journal of Korean Radiological Society. 26(4) 735 - 742. 1990
Malignant vs. Benign Pleural Lesion: CT Findings
Sung-Jin Kim, M.D. , Jung-Gi 1m, M.D. , K iI S un Park, M.D. , Hak Soo Kim , M.D. , Man Chung Han , M.D.
Department o[ RadioJogy' SeouJ NationaJ Un i versity. CoJlege o[ Medicine
〈국문초록〉
악성 흉막 질환과 양성 흉막 질환으I CT 소견
서 울 이| 학교 의파내혁 l앙사선괴혁교실
김 성 진·임 정 기 ·박 길 선·김 학수·한만청
흉막 질환은 염증성 혹은 악성 종양동의 다양한 원인에 의해서 야기되며 이러한 다양한 질환의
감별은 사실상 매우 어렵다. 그러 나 CT 스캔의 영상 행상력이 좋아지면서 흉막병변의 해부학적
충에 따른 변화를 분석함이 가능하게 되였다. 연자퉁은 고해상 CT를 포함한 CT 스캔 영상에서
질환별 소견의 차이를 분석하여 그 갇별 점을 찾고자 하였다.
대상은 남자 49명 여자 1 9명 총 68명 이었으며 연령 분포는 4세에서 78세까지로 평균 연령은 49.
4세였다. 질환의 종류는 농흉 ( n=29 ) . 악성 흉막질환( n =2 1 ) , 섬유흉 ( n=9 ) 및 자유 흉막 상출
액 (n=8 ) 이 였 다. CT 스캔상 악성 흉막 질환과 농흉의 전 예에서 벽측 흉막의 비후와 조영 증강이
있었고 섬유흉의 경우에서는 흉막 외 극에 지방동을 포함하는 조직의 축적 이 관찰되었다. 악성 흉
막 병변의 가장 특정적인 소견은 흉막의 소결절성 종괴와 결절성의 전흉막비후(nodular mass
and nodular pleural rind ; 17 / 21, 13 / 21) 흉막 비 후의 단절 (interruption of pleural thickening ;
14 / 21). 공격적 양상의 흉막 삼출액 ( aggress ive fluid collection ; 1 4 / 2 1 ) 과 종격 흉막의 침습
(mediastinal pleural involvement ; 20 / 2 1 ) 이 였 다. 농흉에서는 비후된 흉악이 전장에 걸쳐 서 평
활하고 두께가 일정하였으며 (25/3이 벽측 흉막과 흉내근막 사이인 흉막 외 극에 조직축적
(extrapleural tissue accumulation ; 1 8 / 30 ) 이 있는것이 가장 흔한 CT 소견이 었다.
이상의 결과에서 CT 스캔은 양성과 악성 흉막 질환의 감별에 상당히 도움이 될것이라고 사료
된다.
Index Words: Pleura. CT . 66. 1211 Pleura. f1uid. 66.76 Pleura. infection . 66.20 Pleura. Neoplasm. 66.32
Introduction or metastatic maJignancies . Although th e pro
gress in the development of a real t ime scanners
has expanded th e appJication of ultrasonography
in pleur외 pathology. pleural lesion s are difficult
to differentiate u s ing coventional imaging me
thods 1.21. Especialiy plural effu s ions associated
with neoplasms are caused by several different
Pleural les ions are caused by a variety of dise
ases, including in f1ammatory diseases. primary
이 논문은 1990년 5월 1 일 접수하여 1 990년 5월 28일에
채택되었음
Received May 1. accepted May 28. 1990
m …
- 大韓放射線醫學會註 第 26 卷 第 4 號 1990 -
mechanisms : direct involvement of the pleural
surfaces by tumor , lymphatic or venous obstruc
tion , endobronchial obstruction with atelectasis ,
postobstructive pneumonitis with a parapne
umonic effusion and severe hypoproteinemia.
These latter four etiologies account for a large
percentage of the negative cytologic and pleural
biopsy findings in these patients3l .
Because of the improvement of resolution po
wer of CT scan , it becomes possible to analyze
the changes of pleural space , layer by layer. 50,
CT scan is well suitable for detection and char
aterization of pleural disaese by analyzing the
changes of anatomical layers. But the appea
rences of pleural disease at CT scan have not
been extensively described and are less well
known. To identify the reasonable criteria in dif
ferential diagnosis of pleural diseases , we revie
wed the CT scans of 68 patients with docu
mented pleural diseases.
Materials and Methods
We reviewed chest CT of 68 patients showing
evidence of pleural pathology or pleural fluid at
chest radiography without regard to any specific
diagnosis between Januarγ 1988 and February
1990. This study group consisted of 19 female
patients and 49 male patients ranging in age
from 4 to 78 years(mean age , 49.4 years). 29 pa
tients had empyema, 21 patients had pleur머
malignancy such as mesothelioma (n= 3 ) or pleu
ral metastasis associated with extrapleural pri-
Table 1. Diagnostic Methods
Pleural Biopsy Cytology
Malignancy 8 14 Empyema 7 o Fibrothorax 0 0 Free Fluid 0 0
Total 15 14
- 736
mary malignancies (n= 18) , 10 patients had fib
rothorax , and 8 patients had free pleural effu
sion without other pleural pathology.
Diagnoses were confirmed by operation , pleu
ral biopsy , cytology of pleural fluid , bacteriolo잉r,
or clinical history and course(Table 1). In mali
gnant pleural lesions , the diagnosis was con
firmed by pleur외 biopsy (n=8 ), cytology of pleu
ral fluid (n= 14 ), and operation (n= I) . The di
agnosis of empyema was based on pleur떠 biopsy
(n=7 ), operation (n= 6 ), bacteriolo잉r of pleural
fluid and sputum (n= 12 ), and compatible clinic
al course and follow up radiography after treat
ment (n=5 ).
61 patients were scanned on a GE 9800 scan
ner(Geberak Electric Medical 5ystem , Milwau
kee). In the remaining patients scans were done
on Tosiba 80-A (n=4 ), Siemens Somatom DRG
(n=2 ), and Shimadzu SCT 2000 T-ll (n= 1). In
48 patients , contiquous 1 cm thick CT scan was
obtained from the apex to the base of the lung.
In 12 patients , high resolution CT scan was per
formed with a GE 9800 CT scanner(l .5 mm col
limation, 140 KVp , 170 rr머, 3 seconds). Both
methods were obtained in 8 patients. An intra
venous bolus of contrast dye(Telebrix 30 Meglu
mine , 2 m l/Kg) was given to all patients
CT scans were evaluated to assess the fol
lowing signs; 1) nodular pleural rind , 2) no
dular mass , 3) interruption of pleural thicke
ning, 4) aggressive fluid collection, 5) medias
tinal pleural involvement , and 6) tissue char
ateristics of extrapleural space. We defined the
Clinical B없ac따teriology Operation Course
0 l 0 12 6 5 0 9 O o 8
12 8 22
- Sung-Jin Kim. et al. Malignant vs. Benign Pleural Les ion ' CT Findi ngs
interruption of pleural thickening as focal dis
continui앙 of diffuse pleural thickening‘ and the
aggressive f1uid collection as mutiloculated f1uid
collection which has abrupt bulging contoured
tense f1uid collection. acute angle between 10-
culated f1uid and pleura. and extensive atelec
tasis comparing with the amount of f1uid. Ple
ural thickening was thought to be presen t, if
there was visible soft tissue stripe between rib
and lung. Because visceral pleural involvement
could not definitely evaluate due to associated
atelectasis. we evaluated parietal pleura only. CT
density of exrtapleural tissue was compared with
adjacent fat. muscle. and f1uid
Results
AlI cases of the malignant pleural lesion and
empyema showed pleural effusion. thickened
parietal pleura and enhancement. But in the
cases of free f1uid. pleural thickening and con
trast enhancement was not identified . The cases
of fibrothorax revealed extrapleural fat accumu
lation and none of these showed pleural f1uid
(Fig. 1).
Malignant pleural lesions
The most charateristic CT features of malig
nant pleural lesions included nodular mass at
tached to parietal pleura( 17/21). nodular pleur외
rind( 13/21 ), interruption of pleural thicken-
Table 2. CT Findings in Pleural Lesions
Fig. 1. This 35-year old man had left sided tuber culous pleurisy 23 years earlier. CT scan reveals a thickened pleura and calcification without f1uid collectin. Fatty tissue(arrow) is seen between the calcified pleura and inner chest wal1 .
ing(l4/2 1), aggressive f1uid collection(l 4 /21 )
and mediastinal pleural involvement(20/21). Ex
trapleural tissue ranged in density from fat to
muscle was demonstrated on CT in only 5 pa
tients(Table 2).
Empyema
The most common findings were diffuse. uni
form and smooth surfaced pleural thickening
Findings Malignancy( %) Empyema(%) n=21 n=29
14(66.7) O (0)
17(8 1.0) 5(17.2)
13(6 1.9) 1 (3 .4)
14(66.7) 2 (6.9)
20(95.2 ) 6(20.7)
5(23 .8) 18(62.1)
lnterruption of Pleural Thickening
Nodular Mass
n
e 뼈 뼈
… α ·
밍 야
“ 띠 m
않
따 ’ m mn
T
뻐 Jm
뻐 때
빼 앉 뼈 빼
M… 며 M
E
η
- 大障放射線뚫學會픔 : 第 26 卷 第 4 號 1990 -
and contrast enhancemen t. which were present Table 3. Analysis of Extrapleural Tissue
in all cases(Fig. 2). Nodular pleural thickening
was a rare finding of empyema and seen in only
5 patients with tuberculous empyema(Fig. 3). In
contrast to the malignant pleur외 lesions , aggres
sive f1uid collection (n=2) , nodular pleur려 rind
(n= 1). nodular mass (n=5). intertuption of
pleural thickening (n=O). and mediastinal ple
ural involvement (n=6) were unusua1 fin-
dings(Table 3). Another characteristic finding of between the chest wall and pleura, which was
empyema was extrapleural tissue accumulation observed in 18 patients. This was a more pro-
nounced feature in tuberculous empyema than
in nontuberculous ones(Fig. 4). The densities of
the accumulated tissue were ranged from fat to
muscle , but mainly were that of fat(1 5/18).
Fig. 2. CT scan in a patient with a tuberculous empyema confirmed by operation shows diffuse , uniform thickening and contrast enhancement of pleura.
Fig. 3. 1.5 mm collimation scan reveals nodular pleural thickening in a patient with a tuberculous empyema. But, note the fatty tissue beneath the thickened pleura(arrow)
Density Malignancy( %) Empyema(%) n=21 n = 29
Fluid 2(9.5) 4(13.8)
Muscle 1(4.8) O( 0)
Fat 2(9.5) 15(5 1. 7)
Total 5(23.8) 19(5 1.5)
Sensitivity and Specificity
The sensitivity and specificity of each finding
for malignant pleural diseases were as follow;
77.3 % and 84.5 % for nodular mass , 92.9 % and
76.5 % for nodular pleural rind , 100 % and 79.4
% for interruption of pleur외 thickening, 87.5 %
and 78.1 % for aggressive fluid collection , 74'.1 %
Fig. 4. 1.5 mm collimation scan with a tuberculous empyema reveals a linear fatty tissue(arrow) beneath the smooth thickened pleura with a lenticular fluid collection. These are characteristic findings of empyema(especially, tuberculous empuema)
m
ω
- Su ng- Ji n Kim , et al. : rvlalignant vs . Benign Pleural LeS10n : CT Fi ndi ngs-
and 95 , 5 % for mediastinal pleural involvement on its luminal margin7.8l, The explanations are
and 78 , 3 % and 64 , 0 % for extrapleural tissue as followings ‘ as an empyema progresses. a fib-
accumulation. respectively , The most sensitive rin peel coats the visceral and pariet외 pleural
and specific finding were interruption of pleural surfaces , This peel organizes with ingrowth of
thickening and mediastinl pleural involvemen t. capillaries and fibroblasts as early as 7 days after
respectively. the onset of disease. forming the split pleura
sign representing visualization of smooth thic-
Discussion kened. separated visceral and parietal pleural
surfaces71. In the malignant pleur외 effusion. pleu
r외 f1uid accumulation is attributed to inceased Normally the pleura and endothoracic fascia
pass internal to the ribs. But they are not visible
in this location on conventional and high resolu
tion CT ‘ Therefore. a soft tissue stripe demons
trated internal to the ribs on conventional CT
can be used to diagnose pleural thickening or
effusion41 . A number of articles have discribed
the CT findings of pleural lesions. including
pleural tuberculosis5,61. empyema7
,81. mesothe
lioma91 . and pleural manifestation of
lymphoma 1ol . But to our knowledge. no large
series except one have compared benign and
malignant pleural lesions focusing to differential
diagnosis , Solanen et a l. described that high
contrast enhancement of the pleura was typical
finding of active pleural disease: this. in com
bination with an infiltrative nature of lesion. was
indicative of malignancy. but benign infectious
process did not show infiltration ll l. Our results
were consistent with observation of Solanen et
a l.
-Nodular mass and nodular pleural rind ;
It is well documented that mesothelioma has
extensive. lobular thickened irregular masses in
volving 외1 pleural surfaces including the medias
tinum9 , 121. A similar configuration can be en
countered in advanced metastatic carcinoma in
volving the pleura91 . And pleural based mass may
be encountered in various malignant diseases
such as lymphoma. metastasis and thymo
ma l 10 , 141 But empyema shows wall charateris
tics that is distinctly thin. uniform and smooth
net filtration of pleural f1uid though serous mem
branes irritated by tumor implants l31.
In our series. nodular mass and nodular pleu
r려 rind was observed in 81.0 % and 61.9 % for
malignant pleur외 lesions. respectively(Fig , 5).
These finding. however. were observed each in 5
and patients with tuberculous empyema.
Therefore these findings may be helpful in the
differential diagnosis between malignant and be
nign pleural lesions.
-Interruption of pleural thickening;
The interruption of pleural thickening was ob
seπed in 14 cases of malignant pleural le
sions(Fig , 6). But this finding was not identified
in the cases of empyema. This finding is the
most sensitive finding of malignancy in our se
ries. but has not been discribed ye t. We consider
that this finding may be caused by uneven dis
tribution and growth of metastatic tumor im
plants and may be the earliest finding of metas
tatic pleural lesion that can be detected on CT.
-Aggressive fluid collection ;
Atypical f1uid collection in the pleural space is
well documented finding in the previously dise
ased pleura such as tuberculosis. But the ag
gressive f1uid collection was more common in the
malignant than benign pleural lesions(Fig. 7) , In
terestingly. 4 cases of these showed nodular
mass or pleur외 thickening abutting the f1uid col
lection(Fig. 8). lt is the possible explanation for
재
/、템 Ij'z 끼 f쐐감섹혐;t : 第 26 잔 第 ι1 꽤 i 99u
this finding that massive fluid collection between
visceral and parietal pleura is loculated by pleu
ral adhesion which is produced by metastatic tu
mor implants. In contrast , this finding is un
usual in the empyema. Therefore , this may be
another helpful finding to differentiate malig
nant from benign pleural lesion.
-Mediastinal pleural involvement;
The mediastinal p leura is especially difficult to
evaluate on conventional imaging modalities.
But mediastinal pleural pathology and other me-
diastinal lesions are well demonstrated by CT a
h Fig. 5. a. CT scan in a patient with a metastatic adenocarcinoma shows uneven thickening and noduar mass(a rrow) . b. CT scan reveals nodular pleural thickening in thc entire pleura including mediast inal and parietal pleura. This patient was confirmed to metastatic adenocarcinima by pleural biopsy
b Fig. 6. a ‘ b : CT scan in a same patient with metastatic adenocarcinoma show discontinuity of pleural thickening. interruption(arrow). It may be the earliest finding of metastatic lesion
Fig. 7. CT scan shows multiple loculated fluid collection with bulging contour and acute angle between loculated fluid and pleura(arrow).
때
- Sung-J in Kim, et al. Malignant vs . Benign Pleural Les ion CT F indings
Fig. 8. CT scan in a patient with metastatic adeno carcinoma shows enhancing nodular mass abutting the f1uid collection(arrow)
scan 11J . Mediastinal p leural involvement in the
mesothelioma has been reported in other arti
cJes9, 12J. But. to our knowledge . only one paper
discribed mediastinal pleural involvement regar
ding the differentiation of malignant from be
nign pleural lesion 15J .
In our s eries . mediastinal pleural invovement
such as loculated f1uid collection. nodular mass
and nod ula r pleural thickening was relatively
common in malignant pleur머 in volvementlFig.
9-AJ. but even loculated pleur혀 effusion was a
rare finding in benign lesion. 6 of our benign
cases showed mediastinal pleural involvement.
and 5 cases of these were tuberculous empye
ma(Fig. 9 -B) . Al though mediastinal pleural in
volvement is the most specific finding of mali
gnancy. it cannot distinctly excJude the possibili
ty of benign lesion. especially tuberculous empye
ma. ConcJusively. this findidng may be helpful in
the diagnosis of malignant p leural lesion.
-Extrapleural tissue accumulation ;
Normally. the layer of fatty connective tissue is
located b etween the parie tal pleu ra and endoth o
racic fascia. This layer is better demonstrated on
h igh resolution CT than on conventional CT. In
most of normal su이ects. however. the intercostal
fat layer is not cJearly seen in all locations4J . In
patients with chronic pleural disease. the CT de
nsity of extrapleur외 tissue in compa rision with
that of adjacent organ or fluid was ranged from
fat to muscJe density. But. in comparision to
malignancy or nontuberculous empyema. the
b Fig. 9. a. CT scan in a patient with metastatic ade nocarcinoma shows f1uid collection in the mediastinal pleura(arrow) , Also noted nodular pleural th ickenine: in the parietal pleura. b , CT scan shows left sided mediastinal pleural thickening(arrow) and nodular pleural rind , Also note pleural thickening on the righ t. This 4 year old girl was ccnfi rmed to tl . Jerculous empyema by pleural biopsy
- 741 -
- 大韓放射線醫學會註、 第 26 卷 第 4 號 1990 -
5. Hulnick DH. Naidich DP. McCauley DI. Pleural
tuberculosis eValuated by computed tomo
graphy. Radiology 1983; 149 : 759-765
6. Schimitt WGH. Hubener KH. Rucker HC. Pleu
ral calcification with persistent effusion. Radio
logy 1983; 149 : 633-638
7. Stark DD. Federle MP. Goodman PC. Podras애
AE. Webb WR. Differentiating lung abscess and
empyema. AJR 1983; 141 : 163-167
8. Baber CE. Hedlung LW. Oddson TA. Putman
CE. Differentiatlng empyemas and peripher떠
pulmonary abscesses. Radiology 1980; 135 :
755-758
9. Rabinowitz JG. Efremidis SC. Chben B et 외.A
comparatine study of mesothelioma and asbes
tosis using computed tomography and conven
tional chest radiography. Radiology 1982 ; 144 :
453-460
10. Shuman LS. Llbishitz HI. Solid pleural mani
festation of lymphoma. AJR 1984; 142: 269-
273
11. Salonen O. Kivisaari L. Stadertsklold-Norden
stam CG. Somer K. Mattson K. Tammilehto L
Computed tomography of pleural lesion with
speCl허 reference to the mediastinal pleura. Acta
Radiol 1986 ; 27 : 527-531
12. Kreel L. Computed tomography of the lung and
pleura. Semin Rentgenol 1978; 13 : 213-225
1. Steinberg lN. Erwin BC. Metastasls to the 13. Leff AL. Hopewell PC. Costello J. Pleural effu-
pleura: Sonographic detectlon. JCU 1987; 15: sion from malignancy. Ann Intern Med 1978;
276-279 88 : 532-537
2. Martinez OC. Serrano BV. Romero RR. Real-ti- 14. Kim HJ. 1m JG. Lee JH. CT manifestation of
me ultrasound evaluation of tuberculous pleur외 thymomas : benign versus invasive thymomas.
effusions. JCU 1989; 17 : 407-410 The journal of the korean radiological society
3. Chernow B. Sahn SA. Carcinomatous involve- 1988; 24 : 775-781
ment of the pleura an analysis of 96 patlents. 15. Leung AN. Muller NL. Miller RR. Differential di-
Am J Med 1977; 63 : 695-702 agnosis of diffuse pleural disease with CT
4. 1m JG. Webb WR. Rosen A. Gamsu G. Costal Radiology RSNA ’89 scientiflc program 1989;
pleura : Appearances at high resolution CT. 173(p) : 139
Radiolo밍, 1989; 171 : 125-131
cases of tuberculous empyema showed mainly fat
density. We believe that extrapleural fat accumul
ation may indicate rather a chronic process of
the diseases and fluid accumulation a more
acute process . Therefore. the extrapleural fat ac
cumulation looks to represent rather a benign
than a malignant disease.
Conclusion
Pleural thickening and enhancement indicate
active pleural lesion either benign or m외ignant.
Nodular mass. nodular pleur외 rind . interruption
of pleural thickening. aggressive fluid collection
and mediastinal pleural involvement are chara
terestic findings of malignant pleural involve
ment are charaterestic findings of malignant le
sion. In contrast. diffuse. smooth and uniform
pleural thickening with or without extrapleural
fat accumulation indicated benign pleur외 lesion.
8ased on these findings presented in this report.
CT is thought to be helpful to differentiate mali-
gnant from benign pleur외 lesions.
REFERENCES
… κ