Methods: Between July 2013 and July 2018, medical data of a total of 31 patients (26 males, 5 females; mean age 27.7±8.2 years; range, 18 to 56 years) who underwent radical surgery for a giant mediastinal tumor in our center and 47 cases (26 males, 21 females; mean age 45.4±16.7 years; range, 19 to 62 years) of giant mediastinal tumors retrieved from the National Center for Biotechnology Information database were retrospectively reviewed. Two-year overall survival and disease-free survival rates of the patients were evaluated.
Results: All patients underwent radical surgery (R0 resection). Symptoms caused by giant mediastinal tumors were relieved after radical surgery during follow-up. The two-year overall survival and disease-free survival rates were 100% and 86.7%, respectively, indicating a good prognosis. The surgical procedures for malignancies were more difficult than those for benign pathologies.
Conclusion: Radical surgery is the mainstay for treatment of giant mediastinal tumors to relieve symptoms in a short period of time and to achieve a good prognosis for up to two years, regardless of adjuvant therapy. The surgical route should be cautiously planned before radical surgery to reduce complications.
Angelopoulos et al.[3] reported an old female with a huge mediastinal malignant schwannoma who suffered from systemic sepsis and multiple organ dysfunction after surgery. A similar case was also reported by Furák et al.[5] in a young female with a large ganglioneuroma suffering from an acute paraplegia with a spinal cord lesion due to vertebral artery injury.
Up to date, there is no similar study including meta-analysis, randomized-controlled trials, and systemic retrospective or observational studies. In this study, we aimed to evaluate the surgical treatment outcomes of GMTs and to develop an evidence-based strategy for the treatment of GMTs.
Forty-seven cases of GMTs reported between January 2008 and December 2018 were retrieved from the NCBI database (https://www.ncbi.nlm. nih.gov/). Among these tumors, 23 were malignant and 24 benign. The malignant tumors consisted of nine liposarcomas,[4-13] five thymomas (Masaoka Stage II-III),[14-18] three schwannomas,[19,20] one gangliocytoma,[21] one angiolipoma,[22] one endodermal sinus tumor,[23] one epithelioid angiosarcoma,[24] one stromal tumor,[25] and one solitary fibrous tumor.[26] The benign tumors included five mature teratomas,[27-31] five schwannomas,[2,32-35] five t hymolipomas,[36-40] two leiomyomas,[41,42] two thymomas (Masaoka Stage I),[43,44] one pericardial cyst,[45] one germ cell tumor,[46] one cavernous hemangioma,[47] one lymphangioma,[48] and one pericardial paraganglioma.[49]
Tumor pathology was determined by two pathologists at the Department of Pathology of Chongqing Medical University. Seventeen tumors were reported as malignant (6 thymomas [Masaoka Stage I-III], two liposarcomas, two teratomas, two thymic squamous cell carcinomas, 2 fibrous histiocytomas, 2 spermatocytomas, and 1 non-Hodgkin lymphoma), while 14 were reported as benign (5 mature teratomas, 2 substernal goiters, 2 schwannomas, 2 solitary fibrous tumors, 1 case of Castleman disease, 1 case of fibromatosis, and 1 thymolipoma).
In terms of the tumor location, two tumors originated from the neck and extended toward the anterosuperior mediastinum. One tumor originated from the superior and anterior mediastinum and extended toward the neck. Five tumors originated from the superior mediastinum and extended toward one hemithorax. Twenty-three tumors were located primarily in one hemithorax.
All patients underwent RS. The surgical route was determined based on the tumor location and the invaded structures. Radical surgery (R0 resection) of a malignant tumor was defined as removal of all invaded structures along with the tumor itself, while RS of a benign tumor was defined as removal of the tumor only. Adjuvant therapy (AT) protocols after RS were decided by a multidisciplinary team consisting of physicians, oncologists, and surgeons.
Prognosis was evaluated based on two-year overall survival (OS) and two-year disease-free survival (DFS) rates. Two-year OS was defined as the percentage of patients who survived for at least two years after RS, while two-year DFS was defined as the percentage of patients who survived for at least two years after RS with no relapse or metastasis.
Statistical analysis
Statistical analysis was performed using the IBM
SPSS for Windows version 19.0 software (IBM Corp.,
Armonk, NY, USA). Descriptive data were expressed
in mean ± standard deviation (SD), median (min-max)
or number and frequency. The Student"s t-test was
used to analyze significant differences between the
groups. The chi-square test was used to analyze
differences between the malignant and benign tumor
groups. Survival analysis was carried out using the Kaplan-Meier plot. A p value of <0.05 was considered
statistically significant.
Table 1: Clinical symptoms of GMTs in our cohort and cases retrieved from NCBI database
The invaded structures, surgical modes, and routes are listed in Table 2. None of the benign tumors involved the surrounding tissues. However, the malignant tumors invaded different tissues in both our cohort and the cases retrieved from the NCBI database. The invaded tissues included vessels (i.e., SVC, innominate vein, subclavian artery, aorta, and pulmonary artery), diaphragm, lung, pericardium, esophagus, nerves, and thoracic wall. The surgical route was determined based on the tumor location and the invaded tissues. A lateral incision was the most common route, as most tumors were primarily located in one hemithorax. A collar incision was added, if the neck was involved. A clamshell or bilateral incision was a more optimal choice, if the tumor extended toward both hemithorax. In our cohort, piecemeal resection was more commonly used for malignancies (p=0.005). However, among the cases retrieved from the NCBI database, there was no significant difference in the use of en bloc resection between malignant and benign tumors (p=0.087), as nearly all surgical procedures included en bloc resection.
Table 2: Clinical data of our cohort and cases retrieved from NCBI database
Demographic characteristics of both cohorts and associated complications are summarized in Table 3. In our cohort, patients with malignancies were likely to be younger than those with benign tumors (p=0.019), while there was no significant difference in the age among the cases retrieved from the NCBI database (p=0.22). The mean maximum diameter of malignant tumors was higher than that of benign tumors in our cohort (p=0.039), while there was no significant difference among the cases retrieved from the NCBI database (p=0.44). Compared to benign tumors, malignancies had a longer mean duration of RS (218.8±57.8 min vs. 162±21.8 min, respectively; p=0.002), chest drainage (5.9±1.6 days vs. 4 .5±0.6 d ays, r espectively; p =0.004), h ospital stay (7.9±1.6 days vs. 6.5±0.6 days, respectively; p=0.004), and a higher amount of intraoperative blood loss (1,550±828 mL vs. 1,023±147 mL, respectively; p=0.023). There was no mortality during the perioperative period. Arrhythmias after RS were relieved and eliminated during the follow-up period without medical intervention. Chylothorax occurring after RS was eliminated by fasting and administration of somatostatin for three days. The use of AT after RS is also shown in Table 3. Seven patients refused to receive AT after RS. No neo-AT or radiotherapy was used.
Table 3: Demographic and clinical data of GMTs in our cohort and cases retrieved from NCBI database
The patients diagnosed with benign tumors survived with no relapse or metastasis since the last follow-up (Table 3). All 17 patients with malignant tumors survived since the last follow-up, of whom 13 remained disease-free. However, one of 17 patients diagnosed with a thymoma (Masaoka Stage III) developed pulmonary metastasis two years after RS, while two others diagnosed with thymic squamous carcinomas and one with a liposarcoma had a relapse at 1.5, 1.2, and two years after RS, respectively. The patients with pulmonary metastasis or relapse refused a second RS and, thus, only received palliative care. The two-year OS rate for malignancies was 100% (17/17), while the two-year DFS was 86.7% (15/17) (Figure 1). Of the cases retrieved from the NCBI database, only one diagnosed with a liposarcoma had a relapse at 1.25 years after RS and underwent a second RS and survived disease-free for another three years. In our cohort, two of 10 patients who received AT had a relapse after RS, while two others who received no AT developed pulmonary metastasis and relapse, respectively. There were no significant differences in the incidences of relapse and metastasis between the patients who receive and did not receive AT (p=0.682). Of the 13 cases retrieved from the NCBI database who received no AT, only one had a relapse, while none developed metastasis. In our cohort, there was no significant difference in the mean DFS duration between the two patients who relapsed after AT and the two patients who relapsed or developed metastasis without AT (1.8±0.4 years vs. 2.1±1.3 years, respectively; p=0.83).
In our cohort, four patients diagnosed with malignancies developed SVC syndrome. The pathology of these patients included one case of thymic squamous cell carcinoma, one thymoma (Masaoka Stage III), and one malignant teratoma. The mean DFS and OS times were 2.3±0.5 and 2.8±1.0 years, respectively. All four of these patients received chemotherapy after RS and survived since the last follow-up. Recurrence occurred in one patient diagnosed with thymic squamous cell carcinoma at two years after RS, while the other three patients remained disease-free.
Radical surgery can relieve or eliminate symptoms during follow-up and improve quality of life of patients. In our cohort and the cases retrieved from the NCBI database, benign tumors primarily caused squeezing symptoms of dyspnea, cough, dysphagia, nausea, and vomiting.[37] Meanwhile, malignancies are associated with invasive and systemic symptoms in addition to squeezing symptoms, such as chest pain, hemoptysis,[21,23] and palpitation.[4,18,20] Under emergent circumstances, such as acute respiratory failure[3] and SVC syndrome, RS can be a life-saving option. In our cohort and the cases retrieved from the NCBI database, the symptoms of squeezing and invasion were relieved during a short-term follow-up after RS. Acute SVC syndrome may also result in sudden death. In our cohort, SVC syndrome of four patients was relieved within two weeks after RS. The GMTs, regardless of benign or malignant, may accompany endocrinological or hematological disorders such as hyperparathyroidism and chronic dyserythropoietic anemia.[50,51] Cooley anemia in our cohort was gradually rectified by RS during follow-up.
Currently, RS remains the first-choice option for treatment of GMTs. However, the surgical route and strategy are critical for surgical safety and successful R0 resection. A lateral thoracotomy is recommended for tumors primarily located in one hemithorax,[2,3] while median sternotomy is recommended for tumors at the anterosuperior mediastinum.[7,12] The hemi-clamshell procedure should be considered, if the tumor is located at the anterior mediastinum and extends into one hemithorax,[6,15] while the clamshell or bilateral thoracotomy is recommended, if the tumor extends into the bilateral hemithorax.[10,40] A collar incision should be considered, if the tumor involves the neck,[33] while acollar incision plus median sternotomy is recommended, if the tumor is located at the anterosuperior mediastinum and involves the neck.[8] Mini-invasive techniques are not recommended for resection of GMTs, except for cystic lesions or solid lesions located at the posteroinferior mediastinum, which has a larger space.[16,30]
Mediastinal tumors may adhere to or invade the surrounding tissues including the vessels, lung, thoracic wall, diaphragm, and pericardium.[9] To achieve R0 resection, the tumor and the invaded surrounding tissues should be completely removed. Injury to the vital tissues (e.g., great vessels and recurrent laryngeal nerve) should be avoided during RS. Therefore, the surgical route and mode should be cautiously planned. Furthermore, extracorporeal membrane oxygenation or cardiopulmonary bypass is recommended, if angioplasty or prosthesis replacement is required.[10,24] Piecemeal resection is an alternative option, if the tumor cannot be removed en bloc, due to the high risk of massive hemorrhage or injury to vital tissues.[30,52]
The main limitations of the present study include its retrospective and single-center design with a small sample size. Therefore, further large-scale, multi-center, prospective studies are needed to confirm these findings.
In conclusion, radical surgery is the paramount strategy for the treatment of giant mediastinal tumors to relieve symptoms within a short period of time and achieve a good prognosis in the long-term. The surgical route and mode should be cautiously planned before RS to reduce the rate of intraoperative complications. We believe that the outcomes of this study provide evidence to guide the treatment of giant mediastinal tumors in clinical practice.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect to
the authorship and/or publication of this article.
Funding
This study was supported by the National Natural Science
Foundation of China (81400590).
1) Schweigert M, Kaiser J, Fuchs T, Stein HJ. Thymoma within
a giant congenital thymic cyst. Interact Cardiovasc Thorac
Surg 2011;13:442-3.
2) Das A, Choudhury S, Basuthakur S, Mukhopadhyay A,
Mukherjee S. Massive hemoptysis: a rare presentation of
posterior mediastinal, giant, benign vagal schwannoma. Arch
Iran Med 2014;17:779-82.
3) Angelopoulos E, Eleftheriou K, Kyriakopoulos
G, Athanassiadi K, Rontogianni D, Routsi C. A Giant
Intrathoracic Malignant Schwannoma Causing Respiratory
Failure in a Patient without von Recklinghausen's Disease.
Case Rep Med 2016;2016:2541290.
4) Arrarás-Martínez MJ, Rieger-Reyes C, Panadero-Paz
C, Landa-Oviedo HS, García-Tirado J. Giant primary
mediastinal liposarcoma: A rare cause of atrial flutter. Asian
Cardiovasc Thorac Ann 2015;23:1121-4.
5) Furák J, Géczi T, Tiszlavicz L, Lázár G. Postoperative
paraplegia after resection of a giant posterior
mediastinal tumour. Importance of the blood supply in
the upper spinal cord. Interact Cardiovasc Thorac Surg
2011;12:855-6.
6) Okuno M, Kawashima M, Miura K, Kadota E, Goto S,
Kato M. Resection of giant mediastinal liposarcoma using
the hemiclamshell incision. Gen Thorac Cardiovasc Surg
2010;58:654-6.
7) Vanoverbeke H. Resection of giant mediastinal liposarcoma.
Acta Cardiol 2014;69:311-2.
8) Taki K, Watanabe M, Iwagami S, Nagai Y, Iwatsuki M,
Ishimoto T, et al. Giant liposarcoma of the posterior
mediastinum and retroperitoneum. BMJ Case Rep
2011;2011:bcr0620114341.
9) Gethin-Jones TL, Evans NR 3rd, Morse CR. Surgical
management of mediastinal liposarcoma extending from
hypopharynx to carina: case report. World J Surg Oncol
2010;8:13.
10) Billè A, Garofalo G, Leo F, Pastorino U. Giant liposarcoma
elongating mediastinal vessels with intrathoracic
inferior vena cava replacement. Eur J Cardiothorac Surg
2013;44:570-2.
11) Ma J, Zhang HM, Zhang LW, Zheng MW, Yu M. Primary
mediastinal giant liposarcoma with smooth muscle and neural
differentiation: A case report. Oncol Lett 2015;9:2667-9.
12) Huang W, Jiang GN. Resection of giant mediastinal
liposarcoma via ?dash shape? incision. J Surg Case Rep
2017;2017:rjw219.
13) Lin F, Pu Q, Ma L, Liu C, Mei J, Liao H, et al. Successful
resection of a huge mediastinal liposarcoma extended to the
bilateral thorax. Thorac Cancer 2016;7:373-6.
14) Filosso PL, Delsedime L, Cristofori RC, Sandri A. Ectopic
pleural thymoma mimicking a giant solitary fibrous tumour of
the pleura. Interact Cardiovasc Thorac Surg 2012;15:930-2.
15) Zhao W, Fang W. Giant thymoma successfully resected via
hemiclamshell thoracotomy: a case report. J Thorac Dis
2016;8:E677-80.
16) Kitada M, Sato K, Matsuda Y, Hayashi S, Tokusashi Y,
Miyokawa N, et al. Ectopic thymoma presenting as a giant
intrathoracic tumor: a case report. World J Surg Oncol
2011;9:66.
17) Spartalis ED, Karatzas T, Konofaos P, Karagkiouzis G,
Kouraklis G, Tomos P. Unique presentation of a giant
mediastinal tumor as kyphosis: a case report. J Med Case
Rep 2012;6:99.
18) Fazlıoğulları O, Atalan N, Gürer O, Akgün S, Arsan S.
Cardiac tamponade from a giant thymoma: case report.
J Cardiothorac Surg 2012;7:14.
19) Su JW, Chua YL, Ong BH, Lim CH. Resection of
a giant malignant mediastinal peripheral nerve sheath
tumour under cardiopulmonary bypass. Singapore Med J
2009;50:e199-200.
20) Wang J, Yan J, Ren S, Guo Y, Gao Y, Zhou L. Giant
neurogenic tumors of mediastinum: report of two cases and
literature review. Chin J Cancer Res 2013;25:259-62.
21) Hayat J, Ahmed R, Alizai S, Awan MU. Giant ganglioneuroma
of the posterior mediastinum. Interact Cardiovasc Thorac
Surg 2011;13:344-5.
22) Liu P, Che WC, Ji HJ, Jiang ZM. A giant infiltrating
angiolipoma of the mediastinum: a case report. J Cardiothorac
Surg 2016;11:164.
23) Chaudhry IU, Rahhal M, Khurshid I, Mutairi H. Radical
surgical resection for giant primary mediastinal endodermal
sinus tumour with pulmonary metastasis after chemotherapy:
can be curative. BMJ Case Rep 2014;2014:bcr2014204662.
24) Tane S, Tanaka Y, Tauchi S, Uchino K, Nakai R, Yoshimura
M. Radically resected epithelioid angiosarcoma that
originated in the mediastinum. Gen Thorac Cardiovasc Surg
2011;59:503-6.
25) Tanimura S, Saito Y, Honma K, Koizumi K. Surgical
case of giant malignant mesenchymoma in the posterior
mediastinum that recurred in the bilateral mediastinum.
J Nippon Med Sch 2008;75:212-5.
26) De Raet J, Sacré R, Hoorens A, Fletcher C, Lamote J.
Malignant giant solitary fibrous tumor of the mediastinum.
J Thorac Oncol 2008;3:1068-70.
27) Pattnaik MK, Majhi PC, Nayak AK, Senapati D. A
rare presentation of a huge mature mediastinal
teratoma with right lung cavitation. BMJ Case Rep
2014;2014:bcr2014203835.
28) Zhao H, Zhu D, Zhou Q. Complete resection of a giant
mediastinal teratoma occupying the entire right hemithorax
in a 14-year-old boy. BMC Surg 2014;14:56.
29) Omachi N, Kawaguchi T, Shimizu S, Okuma T, Kitaichi M,
Atagi S, Yoon HE, Matsumura A, et al. Life-threatening and
Rapidly Growing Teratoma in the Anterior Mediastinum.
Intern Med 2015;54:2487-9.
30) Rothermel L, Gilkeson R, Markowitz AH, Schröder C.
Thoracoscopic resection of a giant teratoma compressing
the right heart. Interact Cardiovasc Thorac Surg
2013;17:594-7.
31) Rothermel L, Gilkeson R, Markowitz AH, Schröder C.
Thoracoscopic resection of a giant teratoma compressing
the right heart. Interact Cardiovasc Thorac Surg
2013;17:594-7.
32) Kato M, Shiota S, Shiga K, Takagi H, Mori H, Sekiya M,
et al. Benign giant mediastinal schwannoma presenting as
cardiac tamponade in a woman: a case report. J Med Case
Rep 2011;5:61.
33) Gueldich M, Hentati A, Chakroun A, Abid H, Kammoun
S, M'saad S, et al. Giant cystic schwannoma of the middle
mediastinum with cervical extension. Libyan J Med
2015;10:27409.
34) Wu Y, Zhang J, Chai Y. Giant mediastinal schwannoma
located in the lower right side of the chest. Niger J Clin Pract
2016;19:678-80.
35) Jang JY, Kim JS, Choe JW, Kim MK, Jung JW, Choi JC, et
al. A case of giant, benign schwannoma associated with total
lung collapse by bloody effusion. Tuberc Respir Dis (Seoul)
2013;75:71-4.
36) Mourad OM, Andrade FM, Abrahão P, Monnerat A,
Judice LF. Asymptomatic giant mediastinal mass: a rare case
of thymolipoma. J Bras Pneumol 2009;35:1049-52.
37) Obeso Carillo GA, García Fontán EM, Cañizares Carretero
MÁ. Giant thymolipoma: case report of an unusual
mediastinal tumor. Arch Bronconeumol 2014;50:557-9.
38) Ganesh Y, Yadala V, Nalini Y, Dal A, Raju AD. Huge
mediastinal mass with minimal symptoms: thymolipoma.
BMJ Case Rep 2011;2011:bcr0520102984.
39) Mohan Rao PS, Moorthy N, Shankarappa RK, Bhat P,
Nanjappa MC. Giant mediastinal thymolipoma simulating
cardiomegaly. J Cardiol 2009;54:326-9.
40) Pei G, Han Y, Zhou S, Liu Z. Giant mediastinal thymolipoma
in a patient with Gardner"s syndrome. Thorac Cancer
2015;6:808-11.
41) Uno A, Sakurai M, Onuma K, Yamane Y, Kurita K, Hayashi
I, et al. A case of giant mediastinal leiomyoma with longterm
survival. Tohoku J Exp Med 1988;156:1-6.
42) Haratake N, Shoji F, Kozuma Y, Okamoto T, Maehara Y.
Giant Leiomyoma Arising from the Mediastinal Pleura: A
Case Report. Ann Thorac Cardiovasc Surg 2017;23:153-6.
43) Limmer S, Merz H, Kujath P. Giant thymoma in the anteriorinferior
mediastinum. Interact Cardiovasc Thorac Surg
2010;10:451-3.
44) Saito T, Makino T, Hata Y, Koezuka S, Otsuka H,
Isobe K, et al. Giant thymoma successfully resected via
anterolateral thoracotomy: a case report. J Cardiothorac
Surg 2015;10:110.
45) Akbayrak H, Yildirim S, Simsek M, Oc M. A rare giant
pericardial cyst mimicking a paracardiac mass. Cardiovasc J
Afr 2016;27:e7-e9.
46) Traibi A, Bakkali YE, Hammoumi ME, Kabiri el H. Giant
mediastinal germ cell tumor. Intern Med 2011;50:1261-2.
47) Kaya SO, Samancılar O, Usluer O, Acar T, Yener AG. Giant
Cavernous Haemangioma of the Anterior Mediastinum.
Eurasian J Med 2015;47:216-7.
48) Sokouti M, Rostambeigi N, Halimi M, Rasihashemi SZ.
A huge lymphangioma mimicking pleural effusion with
extension to both chest cavities: a case report and review of
literature. Iran J Med Sci 2015;40:181-4.
49) Yamamoto Y, Kodama K, Yamato H, Takeda M. Successful
Removal of Giant Intrapericardial Paraganglioma
via Posterolateral Thoracotomy. Case Rep Surg
2014;2014:308462.
50) Ishikawa M, Sumitomo SI, Imamura N, Nishida T, Mineura
K. A rare case of mediastinal functioning parathyroid
adenoma removed successfully with thoracoscopy. J Surg
Case Rep 2017;2017:rjx070.