A localized fibrous tumor of the pleura (LFTP) is a slow growing, primary pleural neoplasm unrelated to asbestos exposure, and accounts for fewer than 5% of pleural tumors (1). It occurs in both sexes and in all age groups, but predominantly affects those in the fifth to seventh decades of life. England et al. (2) found that 60%
of these tumors were benign and 40% were malignant, as determined microscopically on the basis of cellulari- ty, pleomorphism, mitotic activity, hemorrhage, and necrosis. Several radiologic descriptions of benign LFTP have been published (3-7), but the radiologic findings of malignant LFTP with chest wall invasion have not been reported. We describe a case in which a malignant LFTP, confirmed pathologically, invade the chest wall.
Case Report
A 60-year-old man with mild chest pain underwent chest radiography, and a large mass was found to occu- py the lower two thirds of the left side of the chest, shift- ing the mediastinum to the right and obliterating the left costophrenic angle (Fig. 1A). CT images depicted a large ( 1 4×17 cm), well-defined, heterogeneously enhanced mass, with destruction of the anterior arc of the left fourth rib and invasion of the left anterior chest wall. In the peripheral portion of the mass lesion, the internal contour of the enhanced vessel was serpiginous or tubu- lar, and in the central portion, there was severe necrosis.
Due to the presence of the mass, the left lower lobe had collapsed, and the mediastinal structure was displaced to the right. Ipsilateral pleural effusion was substantial (Fig. 1B, C). Transthoracic needle biopsy performed at that time showed that a malignant schwannoma was p r e s e n t .
At thoracotomy, a firm, encapsulted mass, measuring 2 0×1 2×10 cm, was found to be attached to the anterior chest wall by a pedicle. The tumor had invaded the adja- cent anterior chest wall, and the anterior arc of the left
J Korean Radiol Soc 2003;49:4 05- 4 0 8
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A Case Report of Malignant Localized Fibrous Tumor of the Pleura with Chest Wall Inva s i o n
1Sung Keun Park, M.D., Seok Jin Choi, M.D., Auh Whan Park, M.D., Yong Woo Kim, M.D., Hae Woong Jeong, M.D., Hye Kyoung Yoon, M.D.2
A localized fibrous tumor of the pleura (LFTP) is a slow growing, rare primary pleur- al neoplasm. Ty p i c a l l y, it takes the form of a well-delineated large mass lesion based on the pleura. Several radiologic descriptions of benign LFTP have been published, but the radiologic findings of malignant LFTP involving invasion of the chest wall have not been reported. We describe a case of malignant LFTP with chest wall invasion, con- firmed pathologically, and rev i ew the literature.
Index words :P l e u r a
Pleura, Computed tomography (CT) Pleura, neoplasms
1Department of Radiology, Busan Paik Hospital, College of Medicine, Inje U n i v e r s i t y
2Department of Pathology, Busan Paik Hospital, College of Medicine, Inje U n i v e r s i t y
Received April 2, 2003 ; Accepted August 8, 2003
Address reprint requests to : Sung Keun Park, M.D., Department of Radiology, Busan Paik Hospital, College of Medicine, Inje University, 633-165, Gaekum-dong, Busanjin-gu, Busan 614-735, Korea.
Tel. 82-51-890-6579 Fax. 82-51-896-1085 E-mail: [email protected]
fourth rib showed mild erosive change without destruc- tion. A cut section of the mass showed that it was yel- lowish white and had a solid, fibrotic or edematous ap-
pearance with central hemorrhage and necrosis (Fig.
1D). Except for the stalk, these findings correlated well with those of CT. Microscopically, the mass was com-
Sung Keun Park, et al: Malignant Localized Fibrous Tumor of the Pleura with Chest Wall Invasion
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A B
C D
Fig. 1. A. Chest radiograph shows a large mass occupying the lower two thirds of the left side of the chest, shifting medi- astinum to the right and obliterating the left costophrenic angle.
B, C. CT images depicted a large (14×17 cm), well-defined, het- erogeneously enhanced mass, with destruction of the anterior arc of the left fourth rib and invasion of the left anterior chest wall (arrow). In the peripheral portion of the mass lesion, the in- ternal contour of the enhanced vessel (arrowhead) was serpigi- nous or tubular, and in the central portion, there was severe necrosis. Due to the presence of the mass, the left lower lobe had collapsed, and the mediastinal structure was displaced to the right. Ipsilateral pleural effusion was substantial.
D. The mass is relatively well demarcated, and the cut section of the mass showed that it was yellowish white and had a solid, fi- brotic or edematous appearance with central hemorrhage and n e c r o s i s .
E. On microscophic findings, the tumor cells are plump and mi- toses are occasionally found (H & E, ×4 0 0 ) .
E
posed of spindle cells in a fascicular pattern; there was a focal myxoid zone and cellularity was high, with fre- quent mitoses (more than 4/10 high-power field), consis- tent with a malignant localized fibrous tumor of the pleura (Fig. 1E). The patient was scheduled for radiation t h e r a p y .
D i s c u s s i o n
Tumors of the pleura are classified as either diffuse or localized. Diffuse malignant mesothelioma is the most common primary pleural tumor, and is most often relat- ed to asbestos exposure. The prognosis is poor. In con- trast, a localized fibrous tumor of the pleura (LFTP) is rare, not related to asbestos exposure, and the prognosis after surgical resection is generally good.
The origin of the LFTPs is controversial, with re- searchers arguing in favor of either mesothelial or sub- mesothelial proliferation (2, 8). A recent study found a common characteristic immunophenotype for localized fibrous tumor of the pleura that confirms a mesenchy- mal, nonepithelial origin (8).
The tumor has been found in all age groups but has a peak incidence in individuals aged over 50. It is equally common in men and women. Approximately 50% of pa- tients are asymptomatic (2, 9), the lesion being discov- ered incidentally at routine chest radiography. In symp- tomatic patients, the most frequent manifestations are chest pain, cough and dyspnea, which occur in 40% of such patients. These tumors are frequently associated with extrathoracic manifestations, including hyper- trophic pulmonary osteoarthropathy and hypoglycemia.
The former has been noted in 4-35% of patients, while hypoglycemia is usually associated with very large tu- mors and occurs in less than 5% of patients (2, 9). In our case, neither hypertrophic pulmonary osteoarthropathy nor hypoglycemia occurred.
Macroscopically, LFTP appears as a firm, round to ob- long, gray-white tumor, usually circumscribed by a thin capsule. Approximately 65-80% of LFTPs arise from the visceral pleura, and the rest from the parietal pleura (2, 9). Forty percent are attached to the pleura by a pedi- cle, in which case they are usually benign; most are at- tached to the visceral pleura, but some malignant LFTPs also have a pedicle (2). Most unresectable tumors origi- nate from the parietal pleura. Tumors range in diameter from 1 to 39 cm; those larger than 10cm are more likely to be malignant (2). The tumor in this case was connect- ed to the pleura by a pedicle, but due to severe invasion
of the chest wall, we were unable to identify its origin.
Microscopically, an LFTP is composed of haphazardly arranged fascicles of elongated spindle cells separated by varying amounts of collagen (2, 9). Tumor cellularity varies from one area to another; tumors may be pre- dominantly fibrous and acellular, cellular with less col- lagen, or mixed. Myxoid change or hyalinization occurs in areas of dense collagen tissue, and in large tumors, ar- eas of necrosis and hemorrhage may occur. The fibrous and acellular nature of these tumors makes their diagno- sis at transthoracic needle biopsy difficult (9); the lesion in this present case was initially identified as a malig- nant peripheral nerve sheath tumor after transthoracic needle biopsy, but confirmed as a malignant LFTP after removal, and it appears that for correct diagnosis, surgery is required. England et al. (2) found that 60% of these tumors were benign and 40% were malignant, as determined microscopically on the basis of cellularity, pleomorphism, mitotic activity, hemorrhage, and necro- sis. They have a relatively good prognosis: all benign tu- mors and 45% of malignant tumors respond to surgical excision (2). The majority of unresectable tumors have more aggressive histologic findings and associated pleur- al effusion.
Radiologically, an LFTP appears as a solitary, sharply defined, and sometimes lobulated mass, varying in di- ameter from 1 to 39 cm, and may be located in an inter- lobar fissure or adjacent to the diaphragm, medi- astinum, or chest wall (1, 3-6). The mass is connected to the pleura and classically forms obtuse angles with the chest wall. In case involving large masses or these attached to the pleura by a pedicle, the angles with the chest wall may be acute, mimicking a mass of pul- monary origin (1, 4). Calcification or pleural effusion was evident in four (7%) and ten (17%) of 58 cases re- viewed in the AFIP series (1). Compared with those which are benign, malignant tumors commonly give rise to complications (6), and large tumors may com- press adjacent lung parenchyma and mediastinal struc- tures. The tumor under review was a large mass that compressed the adjacent lung and mediastinum, with ipsilateral pleural effusion, but correct evaluation of its origin was precluded by its large size. Pedunculated tu- mors may be mobile, changing in position according to respiration or posture, or from image to image during se- rial chest radiography (4). In this case, the tumor had a stalk, but the mass was not mobile due to its large size and invasion of the adjacent chest wall.
At CT, a well-delineated, often lobulated mass in con-
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tact with the pleura is typically observed, and on unen- hanced CT scans, soft-tissue attenuation is apparent (3).
Calcification is principally noted in large tumors and is related to areas of necrosis (2), and as a result of the rich vascularization of the tumor, contrast enhancement is usually intense and homogeneous. CT, however, may reveal non-enhancing areas that correspond to necrosis, myxoid degeneration, or intra-tumoral hemorrhage (3).
As on chest radiographs, the angle between the tumor and the chest wall may cause confusion in locating the tumor; this sign is more likely to be helpful in localizing a small lesion, which forms obtuse angles with the chest wall, than large masses, the angles of which are most of- ten acute. With regard to the identification of a pedicle, this was possible in four of 16 patients in a study by Mendelson et al. (10). CT findings that suggest a malig- nant fibrous tumor include a diameter greater than 10cm, central necrosis, and ipsilateral pleural effusion (6). In this present case, accurate determination of the origin of the tumor was not possible due to its large size, but since there was destruction of the adjacent rib and invasion of the chest wall though to a relatively minor extent compared with the tumor’s bulk, it is assumed that the tumor originated from the pleura. In addition, the tumor’s large size and its central necrosis, as well as the presence of ipsilateral pleural effusion and the de- struction and invasion which occurred, suggest the its potential malignancy.
The differential diagnosis of a localized mass abutting or invading the pleura include lipoma, peripheral bron- chogenic carcinoma, and other pulmonary neoplasms
(7). Accurate evaluation of the origin of the tumor is not always possible, but when a tumor is large and there is severe necrosis, invasion of the chest wall, and ipsilater- al pleural effusion, the possibility of a malignant pleural tumor should be considered. Diagnosis based only on transthoracic needle biopsy is inaccurate; for accurate diagnosis and treatment, surgical resection is required.
R e f e r e n c e s
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2. England DM, Hochholzer L, McCarthy MJ. Localized benign and malignant fibrous tumors of the pleura. A clinicopathologic review of 223 cases. Am J Surg Pathol 1 9 8 9 ; 1 3 : 6 4 0 - 6 5 8
3. Lee KS, Im JG, Choe KO, Kim CJ, Lee BH. CT findings in benign fibrous mesothelioma of the pleura: pathologic correlation in nine patients. AJR Am J Roentgenol 1 9 9 2 ; 1 5 8 : 9 8 3 - 9 8 6
4. Dresser TS, Stark Pictorial essay: solitary fibrous tumor of the pleura. J Thorac Imaging 1 9 9 8 ; 1 3 : 2 7 - 3 5
5. Ferretti GR, Chiles C, Cox JE, Choplin RH, Coulomb M. Localized benign fibrous tumors of the pleura: MR appearance. J Comput Assist Tomogr 1997;21:115-120
6. Ferretti GR, Chiles C, Choplin RH, Coulomb M. Localized benign fibrous tumors of the pleura. AJR Am J Roentgenol 1 9 9 7 ; 1 6 9 : 6 8 3 - 686
7. Muller NL. Imaging of the pleura. Radiology 1 9 9 3 ; 1 8 6 : 2 9 7 - 3 0 9 8. Hanau CA, Miettinen M. Solitary fibrous tumor: histological and
immunohistochemical spectrum of benign and malignant variants presenting at different site. Hum Pathol 1 9 9 5 ; 2 6 : 4 4 0 - 4 4 9
9. Briselli M, Mark EJ, Dickersin GR. Solitary fibrous tumors of the pleura: eight new cases and review of 360 cases in the literature.
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대한방사선의학회지 2 0 03;49: 4 05- 4 0 8
흉벽을 침범한 흉막기원의 악성 국한성 섬유종양의 방사선 소견: 증례 보고1
1인제대학교의과대학부산백병원진단방사선과학교실
2인제대학교의과대학부산백병원병리학교실
박성근・최석진・박오환・김용우・정해웅・윤혜경2
국한성섬유종양은흉막에서기원한종양으로천천히성장하며경계가좋고거대한크기를특징으로한다. 양성국한 성 섬유종양에대한 여러가지 방사선 소견에 대한보고가있으나, 흉벽을 침범하는 악성국한성섬유종양에 대한 방사 선학적 소견은 아직 보고 되지 않았다. 저자들은 수술로서 확진된 흉벽을 침범하는 악성 국한성 섬유종양을 경험하였 기에문헌고찰과함께보고한다.
