Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
965
Pictorial
H
Essay
H
H
Malignant Cases Akira
Kawashima1
Malignant plasm
that
countered from
Pleural
50
and
Herman
pleural mesothelioma, is associated
with
with increasing patients
with
Mesothelioma:
a rare and usually fatal neo-
frequency.
exposure,
is being
Pretreatment
pleural
en-
are
at
and Methods
reviewed years).
our
CT findings institution
retrospectively. A definite
in 50 patients
from
history
June
The
1 980
mean
of asbestos
(45
men
through
age was exposure
59
and
five
women)
January 1 990 were years (range, 37-85 was
for breast
cancer.
diagnoses
were
institution.
Malignant pleural mesothelioma (MPM) is a rare and usually fatal neoplasm that is increasing in frequency [1 , 2]. It is associated with exposure to asbestos [i , 2]. The clinical signs and symptoms are nonspecific. The histologic diagnosis of MPM by light microscopy may be difficult and require the aid of electron microscopy and immunohistochemistry. In this essay, we present our experience with pretreatment CT findings in 50 patients, 25 of whom had follow-up studies.
Pretreatment
One patient had had radiation
before The
illus-
Pleuralthickening was found in 46 (92%)of the 50 patients, thickening of the pleural surfaces of the interlobar fissures in 43 (86%), pleural calcifications in 10 (20%), and pleural effusions in 37 (74%). The volume of the involved hemithorax varied appreciably. Contractions of the involved hemithorax was noted in 21 (42%) of 50 patients and contralateral mediastinal shift in seven (14%). Disease beyond the panetal pleura was found in the chest wall (nine patients), mediastinum, lymph nodes, and diaphragm.
seen
(48%).
CT findings
mesothelioma
trated.
Materials
present
in 24
sies.
Twenty
November
1990 036i-803X/90/1
555-0965
© American
verified
patients
Histologic
subtyping
therapy to the thorax 30 years
by more
underwent was
than
one
radical
possible
pathologist
surgery
in 44
at our
and/or
patients.
autop-
The
MPMs
were classified as epithelial (tubulopapillary) in 30, sarcomatoid (fibrous, fibrosarcomatous) in 1 1 and mixed (biphasic) in three [1 , 2]. Twenty-five patients had from two to seven (average, 3.6) followup CT scans. The mean observation period per patient spanned 8.2
,
months
(range,
3-44
Pleural
Disease
Pleural
Thickening
months).
The most common finding was pleural thickening that varied in extent, thickness, and nodularity. This was seen in 46 (92%) of 50 patients. Associated pleural effusions were present in 33 (72%) of the 46 patients. The pleural thickening ranged from nonspecific plaquelike lesions seen in three patients (Fig. 1) to a complete or nearly complete rindlike encasement of the entire lung (Fig. 2). The great variability in pleural thickening can be appreciated on other CT images as well. Focal pleural masses were seen in four patients (8%), all of whom had pleural effusions. The masses ranged from 7 to 1 8 cm in maximum diameter. Two of these four patients had chest wall invasion.
Received March 26, 1990; accepted after revision May 30, 1990. Presented in part at the annual meeting of the Society of Thoracic Imaging, Naples, FL, January 1 Both authors: Department of Diagnostic Radiology, The University of Texas M. D. Anderson Address reprint requests to H. I. Libshitz. AJR 155:965-969,
in 50
I. Libshitz
asbestos
malignant
CT Manifestations
Roentgen
Ray Society
1990. Cancer
Center,
1 51 5 Holcombe
Blvd.,
Houston,
TX 77030.
KAWASHIMA
966
AND
LIBSHITZ
AJR:i55,
November
1990
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Fig. 1.-51-year-old man with an epithelial malignant pleural mesothelioma diagnosed at pleuroscopic biopsy. CT scan shows nonspecific plaques (arrow) abutting right hemidiaphragm.
Fig. 2.-65-year-old man with nant pleural mesothelioma and a tos exposure. CT scan shows pleural thickening involving both ceral pleurae. Pleural effusion is is markedly contracted.
:-
Fig. 3.-85-year-old man with an unclassified malignant pleural mesothelioma. A, CT scan shows infiltrating chest wall mass destroying ribs and associated moderate effusion. B, 15 months after tangential external beam radiation therapy, chest wall mass and effusion have markedly diminished. However, nodular pleural thickening has developed.
In 22 medically treated patients with serial CT scans, interval progression occurred in 1 6, no appreciable change in three, improvement in two, and mixed response in one. Progression of the pleural disease can be seen in Figure 3 in a patient who also had a focal infiltrating chest wall mass that diminished with radiotherapy.
Fissural
Involvement
Thickening of the pleural surfaces of the interlobar fissures was seen in 43 (86%) of 50 patients. Like the pleural involvement elsewhere, this may be seen as thickening and/or nodularity (Fig. 4). However, pleural effusion is difficult to distinguish from true pleural thickening, particularly in the absence of nodularity when the involvement is not extensive. Because of its horizontal orientation, involvement of the minor fissure may be difficult to identify on CT scans.
Pleural
pleural pleural
Fig. 4.-56-year-old man pleural mesothelioma. CT pleural thickening in major right that is contiguous with periphery of lung.
epithelial malighistory of asbesdiftuse, irregular parietal and vispresent and lung
with mixed malignant scan shows nodular interlobar fissure on pleural thickening in
Calcifications
Pleural calcifications were seen in i 0 patients calcifications were seen in the mesothelioma in five, they appear to have originated in a pleural 5). A history of asbestos exposure was present the five. The calcification was stippled in the Calcified plaques in keeping with asbestos-related were seen bilaterally in four patients (Fig. 6). patients had radiologic evidence of pulmonary though thin-section CT scans were not obtained.
Pleural
(20%). The six cases. In plaque (Fig. in three of sixth mass. disease None of our fibrosis, al-
Effusion
Pleural effusions were present in 37 (74%) of 50 patients. The volume of the pleural effusion was estimated as composing less than one third of the hemithorax in 1 8 patients, one
AJR:155,
November
CT
1990
OF
MALIGNANT
PLEURAL
MESOTHELIOMA
967
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Fig. 5.-46-year-old man with sarcomatoid malignant pleural mesothelioma and history of asbestos exposure. CT scan shows calcification in tumor in left chest. Consolidated lung anterior to calcIfied mass was invaded by tumor.
Fig. 6-72-year-old man with mixed malignant pleural mesothelioma (MPM) and history of asbestos exposure. CT scan shows bilateral calcified pleural plaques in keeping with asbestos-related disease. MPM is nodular mass invading chest wall and destroying ribs on right.
-
5
6
Fig. 7.-65-year-old man with epithelial malignant pleural mesothelioma. CT scan shows volume loss in left hemithorax, but there is no mediastinal shift.
Fig. 8-74-year-old man with unclassified malignant pleural mesothelioma (MPM). CT scan shows bulky pleural disease and pleural effusion associated with this right-sided MPM, which has caused contralateral mediastinal shift. Of note is pleural thickening across mediastinum into contralateral hemithorax along aorta.
7 to two thirds of the hemithorax two thirds in four patients.
Volume
of the Involved
in 1 5 patients,
and more
than
Hemithorax
The volume of the involved hemithorax varied appreciably. There was contraction of the involved hemithorax with or without ipsilateral mediastinal shift, no difference between hemithoraces, and increased volume with contralateral mediastinal shift. Contraction of the involved hemithorax was noted in 21 patients (42%). It was associated with ipsilateral mediastinal shift in 1 1 and was without obvious shift in 1 0 (Fig. 7). Other signs of volume loss on CT included narrowed intercostal spaces and elevation of the ipsilateral hemidiaphragm. Contralateral mediastinal shift was seen in seven patients (1 4%). It was due to a large effusion in five patients and both effusion and tumoral mass in two patients (Fig. 8). No difference in the volume of the hemithoraces or position of the mediastinum was seen in 22 patients (44%). A “frozen” mediastinum and loss of volume of the involved hemithorax have been suggested as diagnostic features of malignant pleural mesothelioma [1 , 3]. However, a sufficiently
large pleural effusion and/or bulky mass may cause mediastinal shift to the contralateral side so that volume loss or fixation of a hemithorax need not be present. Serial CT scans in eight patients with contraction of the hemithorax on the initial study showed progressive volume loss in three and no change in five. Two of 1 0 patients with neither mediastinal shift nor volume loss at presentation developed contralateral shift owing to increase in the effusion in one and increase of both the effusion and tumor in the other. Ipsilateral volume loss developed in three of the 1 0. Five remained midline. In no patient with ipsilateral mediastinal shift did the mediastinum return to midline even with progression of disease.
Disease
Beyond
the Parietal
Pleura
MPM spreads primarily by local extension throughout the pleural cavity, with subsequent invasion of the chest wall, mediastinum, and diaphragm, and into the abdomen and retroperitoneum [1 , 2, 4]. Hematogenous metastatic disease is less common [2]. CT is valuable in determining the extent of disease beyond the parietal pleura at the initial evaluation and in the follow-up of patients during treatment [4].
968
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Chest
KAWASHIMA
Wall Invasion
Chest wall invasion was noted in nine patients (1 8%), with obvious rib involvement in five (1 0%) (Figs. 3 and 6). Of interest, chest wall invasion was present in five (45%) of 11 sarcomatoid MPMs, four of which had rib destruction. Serial CT scans revealed development of chest wall invasion in four additional patients and invasion of the dorsal spine in one. Rusch et al. [4], in a surgical series, noted that CT underestimates chest wall invasion and may suggest it when it is not present.
Mediastinal
Invasion
Mediastinal pleural involvement often was associated with pericardial thickening to various degrees. In many cases it was virtually impossible to distinguish pleural disease alone from associated pencardial disease. Pericardial disease is certainly more common than in the eight patients in whom it was proved at either surgery or autopsy (Fig. 9). Three patients developed pericardial effusion. It caused pericardial tamponade in two and was asymptomatic in the third. When involvement of the mediastinal pleura was bulky or extensive, involvement of other mediastinal structures was thought to be likely. Extension of the tumor into the contralateral hemithorax was seen in two patients (Fig. 8).
Lymph
Node
Involvement
All nodal groups were examined with the American Thoracic Society classification, and the sizes of the nodes were noted. Nodes 1 cm or larger in maximum diameter were found in 61 nodal groups in 29 patients. These included 1 3 patients with nodes 1 cm or larger in 1 5 nodal groups of the anterior diaphragmatic (Fig. 10) and internal mammary nodal areas.
Fig. 9.-77-year-old man with epithelial malignant pleural mesothelioma. CT scan shows pericardial and pleural thickening in right hemithorax. Pericardial invasion was proved at surgery.
AND
LIBSHITZ
AJR:155,
November
1990
This indicates not only central lymphatic spread along the course of the tracheobronchial tree but also subpleural and/ or chest wall lymphatic spread of this tumor. Extensive pleural disease frequently enveloped and obscured the nodal anatomy in the hilar and middle mediastinal nodal groups. This was noted in i 5 patients and involved 50 nodal groups. In the 20 cases with either radical surgery or autopsy, the lymph nodes were proved to be involved with metastases in eight. Nodes 1 cm or larger in diameter were proved to be involved in four cases in six nodal groups (Fig. 1 1 ), and nodes less than 1 cm in diameter in four cases in seven nodal groups. Of 22 patients with serial CT scans who were treated medically, new nodes 1 cm or larger in diameter developed in 13 patients in 20 nodal groups.
Diaphragmatic
and lnfradiaphragmatic
Invasion
Thickening of the hemidiaphragm, presumably due to pleural disease, is common. Diphragmatic involvement does not preclude radical surgery; however, spread below the diaphragm does. Direct hepatic involvement was seen in two patients and proved at autopsy in one (Fig. i 2). Direct retroperitoneal extension was present in four patients (Fig. i 3); in two of these it was proved at surgery. This included retrocrural lymphadenopathy, which was seen in three patients (Fig. 14). Serial CT scans revealed new hepatic invasion in one patient who also developed liver and lung metastases (Fig. 15). Rusch et al. [4] found that involvement of the undersurface of the diaphragm was underestimated on CT in operated patients.
Fig. 10.-60-year-old man with epithelial malignant pleural mesothelioma and history of asbestos exposure. CT scan shows extensive anterior diaphragmatic adenopathy on left side (arrows). Ovoid density to right of spine is believed to represent paraspinous lymph node.
Fig. 1 1-65-year-old man with epithelial malignant pleural mesothelioma. CT scan shows 2.0-cm node in right paratracheal region (arrow). Metastases to node were proved at surgery. Nodular, diffuse pleural thickening is seen as well.
AJR:155,
November
1990
CT
OF
MALIGNANT
PLEURAL
MESOTHELIOMA
969
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Fig. 12-72-year-old man with epithelial malignant pleural mesothelioma and history of asbestos exposure. Contrast-enhanced CT scan shows direct extension of malignant pleural mesothelioma into liver as an area of decreased attenuation along lateral aspect of liver. Involvement was proved at autopsy.
Fig. i3.-63-year-old man malignant pleural mesothelioma. direct extension into abdomen of tumor abuts stomach.
Fig. i4.-46-year-old thelioma and history scan shows bilateral of left-sided tumor.
with sarcomatoid CT scan shows on left side. Mass
man with epithelial mesoof asbestos exposure. CT retrocrural nodal extension
Fig. i5.-i5-month follow-up CT scan of patient in Fig. 3 shows large mass with central necrosis in liver. This was presumed to represent metastatic disease as it was not present on the initial study. Direct hepatic invasion and chest wall invasion are also seen laterally on right side. Left renal lesion is a cyst.
REFERENCES 1 . Antman KH. Clinical presentation and natural history of benign and malignant mesothelioma. Semin Oncol i98i;8:3i3-320 2. Brenner J, Sordillo PP, Magill GB, Golbey RB. Malignant mesothelioma of the pleura: review of 123 patients. Cancer 1982;49:243i-2435
4
-k’,.
-
3. Rabinowitz JG, Efremidis SC, Cohen B, Dan S, et al. A comparative study of mesothelioma and asbestos using computed tomography and conventional chest radiography. Radiology i982;144:453-460 4. Ausch vw, Godwin JD, Shuman WP. The role of computed tomography scanning in the initial assessment and follow-up of malignant pleural mesothelioma. J Thorac Cardiovasc Surg i988;96: 171-177
965
Pictorial
H
Essay
H
H
Malignant Cases Akira
Kawashima1
Malignant plasm
that
countered from
Pleural
50
and
Herman
pleural mesothelioma, is associated
with
with increasing patients
with
Mesothelioma:
a rare and usually fatal neo-
frequency.
exposure,
is being
Pretreatment
pleural
en-
are
at
and Methods
reviewed years).
our
CT findings institution
retrospectively. A definite
in 50 patients
from
history
June
The
1 980
mean
of asbestos
(45
men
through
age was exposure
59
and
five
women)
January 1 990 were years (range, 37-85 was
for breast
cancer.
diagnoses
were
institution.
Malignant pleural mesothelioma (MPM) is a rare and usually fatal neoplasm that is increasing in frequency [1 , 2]. It is associated with exposure to asbestos [i , 2]. The clinical signs and symptoms are nonspecific. The histologic diagnosis of MPM by light microscopy may be difficult and require the aid of electron microscopy and immunohistochemistry. In this essay, we present our experience with pretreatment CT findings in 50 patients, 25 of whom had follow-up studies.
Pretreatment
One patient had had radiation
before The
illus-
Pleuralthickening was found in 46 (92%)of the 50 patients, thickening of the pleural surfaces of the interlobar fissures in 43 (86%), pleural calcifications in 10 (20%), and pleural effusions in 37 (74%). The volume of the involved hemithorax varied appreciably. Contractions of the involved hemithorax was noted in 21 (42%) of 50 patients and contralateral mediastinal shift in seven (14%). Disease beyond the panetal pleura was found in the chest wall (nine patients), mediastinum, lymph nodes, and diaphragm.
seen
(48%).
CT findings
mesothelioma
trated.
Materials
present
in 24
sies.
Twenty
November
1990 036i-803X/90/1
555-0965
© American
verified
patients
Histologic
subtyping
therapy to the thorax 30 years
by more
underwent was
than
one
radical
possible
pathologist
surgery
in 44
at our
and/or
patients.
autop-
The
MPMs
were classified as epithelial (tubulopapillary) in 30, sarcomatoid (fibrous, fibrosarcomatous) in 1 1 and mixed (biphasic) in three [1 , 2]. Twenty-five patients had from two to seven (average, 3.6) followup CT scans. The mean observation period per patient spanned 8.2
,
months
(range,
3-44
Pleural
Disease
Pleural
Thickening
months).
The most common finding was pleural thickening that varied in extent, thickness, and nodularity. This was seen in 46 (92%) of 50 patients. Associated pleural effusions were present in 33 (72%) of the 46 patients. The pleural thickening ranged from nonspecific plaquelike lesions seen in three patients (Fig. 1) to a complete or nearly complete rindlike encasement of the entire lung (Fig. 2). The great variability in pleural thickening can be appreciated on other CT images as well. Focal pleural masses were seen in four patients (8%), all of whom had pleural effusions. The masses ranged from 7 to 1 8 cm in maximum diameter. Two of these four patients had chest wall invasion.
Received March 26, 1990; accepted after revision May 30, 1990. Presented in part at the annual meeting of the Society of Thoracic Imaging, Naples, FL, January 1 Both authors: Department of Diagnostic Radiology, The University of Texas M. D. Anderson Address reprint requests to H. I. Libshitz. AJR 155:965-969,
in 50
I. Libshitz
asbestos
malignant
CT Manifestations
Roentgen
Ray Society
1990. Cancer
Center,
1 51 5 Holcombe
Blvd.,
Houston,
TX 77030.
KAWASHIMA
966
AND
LIBSHITZ
AJR:i55,
November
1990
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Fig. 1.-51-year-old man with an epithelial malignant pleural mesothelioma diagnosed at pleuroscopic biopsy. CT scan shows nonspecific plaques (arrow) abutting right hemidiaphragm.
Fig. 2.-65-year-old man with nant pleural mesothelioma and a tos exposure. CT scan shows pleural thickening involving both ceral pleurae. Pleural effusion is is markedly contracted.
:-
Fig. 3.-85-year-old man with an unclassified malignant pleural mesothelioma. A, CT scan shows infiltrating chest wall mass destroying ribs and associated moderate effusion. B, 15 months after tangential external beam radiation therapy, chest wall mass and effusion have markedly diminished. However, nodular pleural thickening has developed.
In 22 medically treated patients with serial CT scans, interval progression occurred in 1 6, no appreciable change in three, improvement in two, and mixed response in one. Progression of the pleural disease can be seen in Figure 3 in a patient who also had a focal infiltrating chest wall mass that diminished with radiotherapy.
Fissural
Involvement
Thickening of the pleural surfaces of the interlobar fissures was seen in 43 (86%) of 50 patients. Like the pleural involvement elsewhere, this may be seen as thickening and/or nodularity (Fig. 4). However, pleural effusion is difficult to distinguish from true pleural thickening, particularly in the absence of nodularity when the involvement is not extensive. Because of its horizontal orientation, involvement of the minor fissure may be difficult to identify on CT scans.
Pleural
pleural pleural
Fig. 4.-56-year-old man pleural mesothelioma. CT pleural thickening in major right that is contiguous with periphery of lung.
epithelial malighistory of asbesdiftuse, irregular parietal and vispresent and lung
with mixed malignant scan shows nodular interlobar fissure on pleural thickening in
Calcifications
Pleural calcifications were seen in i 0 patients calcifications were seen in the mesothelioma in five, they appear to have originated in a pleural 5). A history of asbestos exposure was present the five. The calcification was stippled in the Calcified plaques in keeping with asbestos-related were seen bilaterally in four patients (Fig. 6). patients had radiologic evidence of pulmonary though thin-section CT scans were not obtained.
Pleural
(20%). The six cases. In plaque (Fig. in three of sixth mass. disease None of our fibrosis, al-
Effusion
Pleural effusions were present in 37 (74%) of 50 patients. The volume of the pleural effusion was estimated as composing less than one third of the hemithorax in 1 8 patients, one
AJR:155,
November
CT
1990
OF
MALIGNANT
PLEURAL
MESOTHELIOMA
967
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Fig. 5.-46-year-old man with sarcomatoid malignant pleural mesothelioma and history of asbestos exposure. CT scan shows calcification in tumor in left chest. Consolidated lung anterior to calcIfied mass was invaded by tumor.
Fig. 6-72-year-old man with mixed malignant pleural mesothelioma (MPM) and history of asbestos exposure. CT scan shows bilateral calcified pleural plaques in keeping with asbestos-related disease. MPM is nodular mass invading chest wall and destroying ribs on right.
-
5
6
Fig. 7.-65-year-old man with epithelial malignant pleural mesothelioma. CT scan shows volume loss in left hemithorax, but there is no mediastinal shift.
Fig. 8-74-year-old man with unclassified malignant pleural mesothelioma (MPM). CT scan shows bulky pleural disease and pleural effusion associated with this right-sided MPM, which has caused contralateral mediastinal shift. Of note is pleural thickening across mediastinum into contralateral hemithorax along aorta.
7 to two thirds of the hemithorax two thirds in four patients.
Volume
of the Involved
in 1 5 patients,
and more
than
Hemithorax
The volume of the involved hemithorax varied appreciably. There was contraction of the involved hemithorax with or without ipsilateral mediastinal shift, no difference between hemithoraces, and increased volume with contralateral mediastinal shift. Contraction of the involved hemithorax was noted in 21 patients (42%). It was associated with ipsilateral mediastinal shift in 1 1 and was without obvious shift in 1 0 (Fig. 7). Other signs of volume loss on CT included narrowed intercostal spaces and elevation of the ipsilateral hemidiaphragm. Contralateral mediastinal shift was seen in seven patients (1 4%). It was due to a large effusion in five patients and both effusion and tumoral mass in two patients (Fig. 8). No difference in the volume of the hemithoraces or position of the mediastinum was seen in 22 patients (44%). A “frozen” mediastinum and loss of volume of the involved hemithorax have been suggested as diagnostic features of malignant pleural mesothelioma [1 , 3]. However, a sufficiently
large pleural effusion and/or bulky mass may cause mediastinal shift to the contralateral side so that volume loss or fixation of a hemithorax need not be present. Serial CT scans in eight patients with contraction of the hemithorax on the initial study showed progressive volume loss in three and no change in five. Two of 1 0 patients with neither mediastinal shift nor volume loss at presentation developed contralateral shift owing to increase in the effusion in one and increase of both the effusion and tumor in the other. Ipsilateral volume loss developed in three of the 1 0. Five remained midline. In no patient with ipsilateral mediastinal shift did the mediastinum return to midline even with progression of disease.
Disease
Beyond
the Parietal
Pleura
MPM spreads primarily by local extension throughout the pleural cavity, with subsequent invasion of the chest wall, mediastinum, and diaphragm, and into the abdomen and retroperitoneum [1 , 2, 4]. Hematogenous metastatic disease is less common [2]. CT is valuable in determining the extent of disease beyond the parietal pleura at the initial evaluation and in the follow-up of patients during treatment [4].
968
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Chest
KAWASHIMA
Wall Invasion
Chest wall invasion was noted in nine patients (1 8%), with obvious rib involvement in five (1 0%) (Figs. 3 and 6). Of interest, chest wall invasion was present in five (45%) of 11 sarcomatoid MPMs, four of which had rib destruction. Serial CT scans revealed development of chest wall invasion in four additional patients and invasion of the dorsal spine in one. Rusch et al. [4], in a surgical series, noted that CT underestimates chest wall invasion and may suggest it when it is not present.
Mediastinal
Invasion
Mediastinal pleural involvement often was associated with pericardial thickening to various degrees. In many cases it was virtually impossible to distinguish pleural disease alone from associated pencardial disease. Pericardial disease is certainly more common than in the eight patients in whom it was proved at either surgery or autopsy (Fig. 9). Three patients developed pericardial effusion. It caused pericardial tamponade in two and was asymptomatic in the third. When involvement of the mediastinal pleura was bulky or extensive, involvement of other mediastinal structures was thought to be likely. Extension of the tumor into the contralateral hemithorax was seen in two patients (Fig. 8).
Lymph
Node
Involvement
All nodal groups were examined with the American Thoracic Society classification, and the sizes of the nodes were noted. Nodes 1 cm or larger in maximum diameter were found in 61 nodal groups in 29 patients. These included 1 3 patients with nodes 1 cm or larger in 1 5 nodal groups of the anterior diaphragmatic (Fig. 10) and internal mammary nodal areas.
Fig. 9.-77-year-old man with epithelial malignant pleural mesothelioma. CT scan shows pericardial and pleural thickening in right hemithorax. Pericardial invasion was proved at surgery.
AND
LIBSHITZ
AJR:155,
November
1990
This indicates not only central lymphatic spread along the course of the tracheobronchial tree but also subpleural and/ or chest wall lymphatic spread of this tumor. Extensive pleural disease frequently enveloped and obscured the nodal anatomy in the hilar and middle mediastinal nodal groups. This was noted in i 5 patients and involved 50 nodal groups. In the 20 cases with either radical surgery or autopsy, the lymph nodes were proved to be involved with metastases in eight. Nodes 1 cm or larger in diameter were proved to be involved in four cases in six nodal groups (Fig. 1 1 ), and nodes less than 1 cm in diameter in four cases in seven nodal groups. Of 22 patients with serial CT scans who were treated medically, new nodes 1 cm or larger in diameter developed in 13 patients in 20 nodal groups.
Diaphragmatic
and lnfradiaphragmatic
Invasion
Thickening of the hemidiaphragm, presumably due to pleural disease, is common. Diphragmatic involvement does not preclude radical surgery; however, spread below the diaphragm does. Direct hepatic involvement was seen in two patients and proved at autopsy in one (Fig. i 2). Direct retroperitoneal extension was present in four patients (Fig. i 3); in two of these it was proved at surgery. This included retrocrural lymphadenopathy, which was seen in three patients (Fig. 14). Serial CT scans revealed new hepatic invasion in one patient who also developed liver and lung metastases (Fig. 15). Rusch et al. [4] found that involvement of the undersurface of the diaphragm was underestimated on CT in operated patients.
Fig. 10.-60-year-old man with epithelial malignant pleural mesothelioma and history of asbestos exposure. CT scan shows extensive anterior diaphragmatic adenopathy on left side (arrows). Ovoid density to right of spine is believed to represent paraspinous lymph node.
Fig. 1 1-65-year-old man with epithelial malignant pleural mesothelioma. CT scan shows 2.0-cm node in right paratracheal region (arrow). Metastases to node were proved at surgery. Nodular, diffuse pleural thickening is seen as well.
AJR:155,
November
1990
CT
OF
MALIGNANT
PLEURAL
MESOTHELIOMA
969
Downloaded from www.ajronline.org by 177.226.209.170 on 10/26/15 from IP address 177.226.209.170. Copyright ARRS. For personal use only; all rights reserved
Fig. 12-72-year-old man with epithelial malignant pleural mesothelioma and history of asbestos exposure. Contrast-enhanced CT scan shows direct extension of malignant pleural mesothelioma into liver as an area of decreased attenuation along lateral aspect of liver. Involvement was proved at autopsy.
Fig. i3.-63-year-old man malignant pleural mesothelioma. direct extension into abdomen of tumor abuts stomach.
Fig. i4.-46-year-old thelioma and history scan shows bilateral of left-sided tumor.
with sarcomatoid CT scan shows on left side. Mass
man with epithelial mesoof asbestos exposure. CT retrocrural nodal extension
Fig. i5.-i5-month follow-up CT scan of patient in Fig. 3 shows large mass with central necrosis in liver. This was presumed to represent metastatic disease as it was not present on the initial study. Direct hepatic invasion and chest wall invasion are also seen laterally on right side. Left renal lesion is a cyst.
REFERENCES 1 . Antman KH. Clinical presentation and natural history of benign and malignant mesothelioma. Semin Oncol i98i;8:3i3-320 2. Brenner J, Sordillo PP, Magill GB, Golbey RB. Malignant mesothelioma of the pleura: review of 123 patients. Cancer 1982;49:243i-2435
4
-k’,.
-
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