Asian Cardiovasc Thorac Ann 2008;16:e12-e14
© 2008 Asia Publishing EXchange Ltd
Intimal Sarcoma of Aortic Arch Treated with Proton Therapy Following Surgery
Naoyuki Ishigami, MD,
Kazuchika Suzuki, PhD,
Tsuyoshi Takahashi, PhD,
Hiroshi Neyatani, PhD,
Abul Hasan M Bashar, PhD1,
Teruhisa Kazui, PhD1
Department of Cardiovascular Thoracic Surgery Fujieda Municipal General Hospital Fujieda
1 First Department of Surgery Hamamatsu University School of Medicine Sizuoka, Japan
For reprint information contact: Naoyuki Ishigami, MD, Tel: 81 54 646 1111, Fax: 81 54 646 1122, Email: ishigami-ths{at}umin.net, Department of Cardiovascular Thoracic Surgery, Fujieda Municipal General Hospital, 4–1–11 Surugadai, Fujieda City 426–8677, Japan.
 |
ABSTRACT
|
|---|
Management of a rare case of intimal sarcoma of the aortic arch is reported, which was diagnosed unexpectedly after total arch replacement for pseudoaneurysm. The prognosis for this condition is poor, with death usually within a few months from diagnosis. The newly developed proton-beam radiation therapy was applied to treat a local recurrence of the sarcoma following surgery. Positron-emission tomography/computed tomography revealed complete remission of the lesion.
|
INTRODUCTION
|
|---|
Primary sarcomas of the aorta are extremely rare and difficult to diagnose preoperatively. The prognosis is generally poor, with death resulting in most patients within a few months from diagnosis. We report a case of intimal sarcoma of the aortic arch, diagnosed unexpectedly after total arch replacement for pseudoaneurysm.
|
CASE REPORT
|
|---|
A 49-year-old man was referred to our institution for further evaluation of an abnormal shadow on his chest radiograph. His chief complaint was voice disturbance; left recurrent laryngeal nerve palsy was diagnosed by an otolaryngologist. A chest radiograph showed enlargement of the upper mediastinum. Computed tomography (CT) showed a mass at the lateral aspect of the aortic arch, which appeared to be a pseudoaneurysm filled with a thrombus (Figure 1
). The entire aorta exhibited mild atherosclerotic calcification. There was no evidence of a lung tumor, and the lymph nodes were not enlarged. Urgent surgery for the aortic arch pseudoaneurysm was scheduled for 1 month after the patient presented with hoarseness. Under general anesthesia, a median sternotomy was performed, and cardiopulmonary bypass was instituted with bicaval cannulation. Systemic cooling was initiated immediately, and the aortic arch was opened under hypothermic circulatory arrest. On identifying a perforation in the lesser curvature of the aortic arch, a pseudoaneurysm was diagnosed, and total arch replacement was carried out under selective cerebral perfusion. A whitish mass was observed on the outside of the pseudoaneurysm, most of which was resected with the pseudoaneurysm. Intraoperatively, we had the impression of a weakened aortic wall. The postoperative course was uneventful. Macroscopically, the excised specimen had a rough intima with a perforation (Figure 2A) and a whitish mass (30 x 11 mm) on the outside of the pseudoaneurysm (Figure 2B). On histologic examination of the resected specimen, spindle-shaped atypical cells proliferated in layers on the surface of the atheroma in the intima of the aortic arch. Pathologic findings included pseudoaneurysm formation due to an intimal tear, surrounded by a tumor (30 x 11 mm) of pleomorphic spindle atypical cells. The pathological margins were positive. Immunohistochemical studies were positive for vimentin, 
1-antitrypsin and smooth muscle actin, but negative for CD34 and factor VIII. To our surprise, the histopathological diagnosis was aortic intimal sarcoma. The patient was discharged in good health without further treatment.
View larger version (83K):
[in this window]
[in a new window]
|
Figure 1. Contrast-enhanced computed tomographic scan showing a mass at the lateral aspect of the aortic arch, resembling a pseudoaneurysm filled with a thrombus.
|
|
View larger version (48K):
[in this window]
[in a new window]
|
Figure 2. Gross appearance of the excised specimen; (A) The intimal surface was rough, and a perforation was identified (white arrow); (B) A whitish mass (2 white arrows), 30 x 11 mm, was observed outside the pseudoaneurysm.
|
|
Three months after the surgery, a local recurrence was suspected on CT at our hospital. We consulted an oncologist at Shizuoka Cancer Center. Further investigation using combined positron-emission tomography (PET) and CT (PET/CT) confirmed a local recurrence (Figure 3A). The patient was admitted to Shizuoka Cancer Center to undergo proton-beam radiation therapy with a total dose of 72 Gray-equivalents in 24 fractions. Four months after the irradiation, PET/CT revealed complete remission of the recurrent lesion, with disappearance of uptake (Figure 3B). The patient was in good health without hoarseness 18 months after the initial operation.
View larger version (60K):
[in this window]
[in a new window]
|
Figure 3. Combined positron-emission tomography/computed tomography revealed (A) massive accumulation in the recurrent lesion, and (B) no uptake 4 months after proton therapy.
|
|
|
DISCUSSION
|
|---|
Primary sarcomas of the aorta are extremely rare. Intimal sarcomas of the aorta almost exclusively involve the descending thoracic or abdominal aorta; the aortic arch and its branch vessels are less frequently affected.1 Aortic sarcomas have been classified as intimal and mural types. Mural-type sarcomas may arise in the media or adventitia and usually have a less aggressive although poor clinical course. Intimal-type sarcomas are characterized by more aggressive behavior, leading to death within months; they may form plaques along the aortic intima, or they may grow as polyploid intraluminal vegetations.2
Because of their rarity, aortic sarcomas are not always suspected preoperatively. The initial clinical presentation of aortic sarcomas may be nonspecific, with fever, weight loss and anorexia.2 The most common modes of presentation are embolic phenomena, usually in the lower extremities or intestinal ischemia from occlusion of mesenteric vessels, which require emergency surgical intervention.3–5 Rare manifestations include aneurysm formation and even rupture.6 In this case, the intimal sarcoma of the aortic arch led to pseudoaneurysm and tumor formation outside the aortic arch, with invasion of the adventitia and surrounding tissues. In the absence of metastatic disease, an aggressive surgical approach is warranted.5 However, surgical treatment of patients with aortic tumors is frequently noncurative because they present with advanced disease. The main factors that correlate with a poor prognosis are intimal type, involvement of the ascending aorta, aortic arch, or visceral aorta, and incomplete resection.7 All of these factors applied to our case.
As in this patient, when aortic intimal sarcoma is unexpectedly diagnosed after total arch replacement, the subsequent treatment is difficult. There is no consensus regarding the safety margin for additional surgical resection, and surgical intervention may prove excessive. At this time, there is no clear evidence of a therapeutic benefit from chemotherapy or radiation therapy after surgery.2 Therefore, we considered it preferable to consult a cancer specialist and carefully monitor the patient by PET/CT for any postoperative relapse. The newly developed proton-beam radiation therapy was applied to the local recurrence of the sarcoma. Proton therapy offers a physical advantage over photon therapy. Unlike photons that enter the patient at a relatively high dose and deposit radiation at and beyond the target, protons enter at a low dose and once the proton beam reaches the tumor target, all remaining energy is absorbed by the tumor; no normal tissues distal to the target are irradiated.8 We believe that proton-beam radiation therapy was especially beneficial for treating this local recurrence of aortic intimal sarcoma after total arch graft replacement, as it reduced the risk of late side-effects from conventional radiation therapy.
|
REFERENCES
|
|---|
- Majeski J, Crawford ES, Majeski EI, Duttenhaver JR. Primary aortic intimal sarcoma of the endothelial cell type with long-term survival. J Vasc Surg 1998;27:555–8.[Medline]
- Burke AP, Virmani R. Sarcomas of the great vessels: a clinicopathological study. Cancer 1993;71:1761–73.[Medline]
- Mohsen NA, Haber M, Urrutia VC, Nunes LW. Intimal sarcoma of the aorta. AJR Am J Roentgenol 2000;175:1289–90.[Free Full Text]
- Wright EP, Glick AD, Virmani R, Page DL. Aortic intimal sarcoma with embolic metastases. Am J Surg Pathol 1985;9:890–7.[Medline]
- Higgins R, Posner MC, Moosa HH, Staley C, Pataki KI, Mendelow H. Mesenteric infarction secondary to tumor emboli from primary aortic sarcoma. Guidelines for diagnosis and management. Cancer 1991;68:1622–7.[Medline]
- Neri E, Miracco C, Luzi P, Carone E, Tripodi A, Sassi C. Intimal-type primary sarcoma of the thoracic aorta presenting as a saccular false aneurysm: report of a case with evidence of rhabdomyosarcomatous differentiation. J Thorac Cardiovasc Surg 1999;118:371–2.[Free Full Text]
- Chiche L, Mongredien B, Brocheriou I, Kieffer E. Primary tumors of the thoracoabdominal aorta: surgical treatment of 5 patients and review of the literature. Ann Vasc Surg 2003;17:354–64.[Medline]
- Kirsch DG, Tarbell NJ. Conformal radiation therapy for childhood CNS tumors [Review]. Oncologist 2004;9:442–50.[Abstract/Free Full Text]
TOP
ABSTRACT
INTRODUCTION
