Resection of a posterior mediastinal mass: Lessons learned from a failed exploration for presumed schwannoma

Accepted Manuscript Resection of a Posterior Mediastinal Mass: Lessons Learned from a Failed Exploration for Presumed Schwannoma Samuel Kim, MD, Brian Yoo, MD, Ali Baaj, MD, Alex G. Little, MD PII:

S0022-5223(16)30120-9

DOI:

10.1016/j.jtcvs.2016.04.030

Reference:

YMTC 10527

To appear in:

The Journal of Thoracic and Cardiovascular Surgery

Received Date: 20 October 2015 Revised Date:

28 March 2016

Accepted Date: 10 April 2016

Please cite this article as: Kim S, Yoo B, Baaj A, Little AG, Resection of a Posterior Mediastinal Mass: Lessons Learned from a Failed Exploration for Presumed Schwannoma, The Journal of Thoracic and Cardiovascular Surgery (2016), doi: 10.1016/j.jtcvs.2016.04.030. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

1 2 3

Resection of a Posterior Mediastinal Mass: Lessons Learned from a Failed Exploration for Presumed Schwannoma

5

RI PT

4

Samuel Kim MD1 , Brian Yoo MD1, Ali Baaj MD2,, Alex G. Little MD1

6

1 Division of Cardiothoracic Surgery, University of Arizona, Tucson, AZ; 2 Department of Neurosurgery, New York-Presbyterian/ Weil Cornell Medical Center

SC

7 8

M AN U

9

10

Running title: Considerations for resection of posterior mediastinal mass

11

Keywords: chordoma, multi-disciplinary, considerations

12

Word count= 750

14

TE D

13

Corresponding author:

16

Samuel Kim, MD

17

1501 N. Campbell Ave., Rm 4302

18

Tucson, AZ 85724

19

Phone (520) 419-1535

20

Fax (520) 626-4042

22

AC C

21

EP

15

23

All the authors have no conflict of interest and have nothing to disclose.

24

No funding was provided for this work.

ACCEPTED MANUSCRIPT

25

26

Introduction Surgeons frequently proceed with surgical resection of a paraspinal tumor without biopsy for presumptive diagnosis of schwannoma.1-2 However, misdiagnosis

28

and improper operative planning can have dire consequences for the patients. Here, we

29

discuss our experience with perioperative management and resection of a large thoracic

30

chordoma that was initially misdiagnosed as schwannoma.

31

Clinical Presentation

SC M AN U

32

RI PT

27

A 60-year old male underwent an attempted resection of a left-sided paraspinal mass spanning the level T7-T9 for a presumed diagnosis of schwannoma. A left

34

posterolateral thoracotomy was performed, and a large paraspinal mass was found,

35

invading the spine, abutting the descending aorta. An attempt was made to dissect the

36

tumor off the spine, but “bleeding from intercostal arteries prevented further dissection.”

37

The operation was aborted. An intraoperative incisional biopsy demonstrated chordoma.

38

Magnetic resonance imaging (MRI) and positron emission tomography (PET) scan ruled

39

out spinal cord involvement and distant metastasis, and a two-staged en-bloc surgical

40

resection was recommended.

41

Intervention and Technique

EP

AC C

42

TE D

33

Stage I involved a posterior midline approach to stabilize the thoracic spine by

43

placing pedicle screws above (T6) and below the levels of the lesion (T10). The sagittal

44

cuts were created along the lateral aspect of the lamina/pedicles and deep into the

ACCEPTED MANUSCRIPT

45

vertebral bodies (T7-T9). This in effect dissociated the vertebral segment with tumor

46

from the remainder of the vertebral column.3 Stage II began with a left posterolateral thoracotomy at the sixth intercostal

RI PT

47

space. The 6th- 10th ribs were resected at a distance 4 cm lateral to the edge of the

49

tumor to created a posterior and lateral margin. The descending aorta above and below

50

the tumor was encircled to allow rapid vascular control in the event of bleeding.

51

Medially, several intercostal arteries were ligated and the tumor was freed from the

52

aorta. The dissection was carried dorsal to the ribs until the sagittal cut made from stage

53

I was identified and remaining vertebral body attachments were cut. The lesion along

54

with the lateral vertebral column was fractured out with delivery of the tumor en bloc.

55

The chest wall was reconstructed using Goretex mesh.

56

Clinical Outcome

M AN U

TE D

57

SC

48

The patient was neurologically intact and discharged after 12 days. Initial pathology showed possible microscopic tumor at medical margin; however, re-

59

examination of specimen by senior pathologist confirmed negative final margin. The

60

patient did not receive adjuvant radiation treatment. A follow up MRI after 1 year

61

demonstrated no evidence of recurrent disease.

62

Discussion

63

AC C

EP

58

Paraspinal primary bone tumors, such as chordoma, are rare. Several

64

procedures have been described for resection of thoracic paraspinal tumors including a

65

single-staged midline approach or multiple stages.4-6 The technical operative details of

ACCEPTED MANUSCRIPT

the current case was published previously as well.3 However, most of these earlier

67

reports focused on the neurosurgical techniques of operation. Yet, paraspinal primary

68

bone tumors can be confused with more common schwannoma, and thoracic surgeons

69

are often the first specialist the patients encounter. This case demonstrates the

70

diagnostic and management dilemmas often confronted by thoracic surgeons and offers

71

guidance in avoiding pitfalls.

RI PT

66

This case highlights two crucial errors that were made during our patient’s

73

preoperative diagnosis and management: a wrong diagnosis made solely based on CT

74

imaging and incomplete surgical planning. Both errors could have been prevented with

75

multi-disciplinary team approach. The initial CT scan demonstrated an obliteration of the

76

plane between the spine and the tumor (Figure 1B), which would be unusual for a

77

benign schwannoma. Review of CT images and discussion between the oncologist,

78

surgeon and radiologist could have led to a correct diagnosis. CT guided biopsy and

79

further evaluation using MRI would have been invaluable in narrowing down the

80

differential diagnosis and defining the anatomy for the surgical approach.

M AN U

TE D

EP

81

SC

72

A large chordoma involving the thoracic spine is challenging due to its proximity to descending aorta and requires careful planning by both thoracic surgery and

83

neurosurgery. Major hemorrhage from intercostal arteries can be difficult to control

84

especially if the tumor is large and near the aorta. Preparation for proximal and distal

85

control of the aorta should be planned accordingly. We chose a 2-stage approach,

86

because dissecting the tumor free from the aorta while controlling the intercostal artery

87

branches was a key portion of the operation. The single stage posterior midline

88

approach would have been difficulty if not impossible in our patient.

AC C

82

ACCEPTED MANUSCRIPT

89

90

Conclusion A presumed schwannoma with locally invasive features should be carefully worked up by a multi-disciplinary team to avoid misdiagnosis and pitfalls during the

92

operation. A two-staged approach allows the surgeon to confirm the stability of the

93

spine prior to the tumor resection and gives best exposure with minimal risk.

RI PT

91

SC

94 95

M AN U

96 97 98 99 100

104 105 106 107 108

109

110

EP

103

AC C

102

TE D

101

ACCEPTED MANUSCRIPT

111

112

References 1. Reed, M Technique of thoracoscopic resection of posterior mediastinal tumors. Operative Tech in Thorac and Cardiovasc Surg. 2010: 15(2):114-124.

114

2. Conti P, Pansini G, Moucharty H, Capuano C, Conti R. Spinal neurinoma:

RI PT

113

retrospective analysis and long-term outcome of 179 consecutive operated cases

116

and review of the literature. Surg Neurol. 2004; 61(1): 34-43

117

SC

115

3. Avila MJ, Skoch J, Fennell VS et al. Combined posterior hemiosteotomies and stabilization with lateral thoracotomy for en bloc resection of thoracic paraspinal

119

primary bone tumors: technical note. J Neurosurg Spine. 2016: 24:2:223-227.

120

4. Sciubba DM, Gokaslan ZL, Black JH, et al. 5-level spondylectomy for en bloc

M AN U

118

121

resection of thoracic chordoma: case report. Operative Neurosurg 2011; 69: 248-

122

256.

5. Oppenlander ME, Maulucci CM, Ghobrial GM, et al. En bloc resection of upper

TE D

123

thoracic chordoma via a combined simultaneous anterolateral thoracoscopic and

125

posterior approach. Neurosurgery. 2014;10 Suppl 3:380-386.

127 128 129 130 131 132

6. Sundaresan N, Steinberger AA, Moore F, et al. Indications and results of combined anterior-posterior approaches for spine tumor surgery. J

AC C

126

EP

124

Neurosurg1996;85:438–46.

ACCEPTED MANUSCRIPT

Figure 1: Side-by-side comparison of thoracic chordoma (A) vs. extradural schwannoma

134

(B). Schwannoma is usually lobulated, encapsulated, and well demarcated as shown in

135

Figure B. There is a loss of plane between the spine and tumor in chordoma as shown

136

in Figure A.

137

RI PT

133

Figure 2: Intraoperative photograph of the resected tumor and the operative field after

139

the resection. The arrows indicate ligated intercostal arteries

SC

138

140

AC C

EP

TE D

M AN U

141

B

AC C

EP

TE D

M AN U

A

SC

RI PT

ACCEPTED MANUSCRIPT

RI PT

ACCEPTED MANUSCRIPT

Cranial

M AN U

SC

Cranial

Posterior Anterior

Aorta

AC C

EP

TE D

Anterior

Caudal

Caudal

Spine Posterior