Clinical Imaging 38 (2014) 218–220

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Mediastinal venous vascular malformations: report of two cases, with discussion of imaging findings and classification systems☆,☆☆ Andres Robert a, Daniel Raymond c, Michael Bolen a, b, Rahul Renapurkar a,⁎ a b c

Section of Thoracic Imaging, Imaging Institute, Cleveland Clinic, Cleveland, Ohio Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, Cleveland, Ohio Section of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio

a r t i c l e

i n f o

Article history: Received 10 September 2013 Received in revised form 18 November 2013 Accepted 25 November 2013 Keywords: Venous vascular malformation CT MRI

a b s t r a c t Mediastinal vascular malformations are interesting group of disorders, which are rarely seen in clinical practice. In this case report, we discuss two cases of venous vascular malformations in the anterior and posterior mediastinum. Also, we discuss the findings on cross-sectional imaging and review the classification schemes of these lesions. © 2014 Elsevier Inc. All rights reserved.

1. Introduction Vascular malformations are uncommon lesions, which can be seen in a variety of locations. More commonly seen in the brain and spinal cord, mediastinal vascular malformations are infrequently seen in clinical practice. Most of these patients go unnoticed or present with symptoms secondary to mass effect or compression of the neighboring structures. Venous vascular malformations (VVM) are the most common type of vascular malformations seen in clinical practice [1]. In this case report, we describe two cases of VVMs, one in the anterior mediastinum and the other in the posterior mediastinum. Also, we briefly review the classifications of the vascular malformations and the role of imaging in the diagnosis and treatment of these lesions.

his heart. A repeat CT exam of the chest and abdomen was done at our institution to characterize the pericardiac/cardiac lesion and to assess the renal neoplasm. A heterogenous mass with solid and fat components was noted in the anterior mediastinum extending down to the right cardiophrenic angle (Fig. 1). This mass contained tortuous veins within, which drained into a dilated superior vena cava (SVC) (Fig. 1). Also noted were multiple phleboliths within this lesion. The imaging characteristics were consistent with a venous malformation. The benign nature of this lesion was explained to the patient. However, the patient was anxious about this lesion and wished a histopathological confirmation, for which a surgical biopsy was done (Fig. 2). Surgical specimen revealed tortuous venous vessels and hemosiderin with no evidence of malignancy, confirming the imaging diagnosis. 3. Case 2

2. Case 1 A 54-year-old male presented to our institution with a diagnosis of renal neoplasm and “mass on heart”. He was in his usual state of health until 2weeks prior to presentation, when he had an episode of hematuria. He underwent computed tomography (CT) exam at a local facility as part of the work-up, which revealed a large 6-cm right renal mass. He was also told that he had an infiltrating mass in

☆ Funding: None. ☆☆ Conflicts of Interest: None. ⁎ Corresponding author. Thoracic Imaging, Hb6, Imaging Institute, Cleveland Clinic, Cleveland, OH 44195. Tel.: +1 216 445 0582; fax: +1 216 636 0822. E-mail address: [email protected] (R. Renapurkar). 0899-7071/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.clinimag.2013.11.014

A 32-year-old male with increasing diplopia and unsteady gait since 2008 underwent echocardiography as part of the work-up. This demonstrated a mediastinal mass in the retroesophageal region. To further characterize this lesion, magnetic resonance imaging (MRI) of the chest was performed. MRI revealed a large infiltrating middle mediastinal mass extending from the thoracic inlet to just above the diaphragm and extending to the left hilar region. This lesion contained multiple phleboliths within. The superior aspect of the mass was closely related to the esophagus, which had a thickened wall anteriorly. Also noted was mild extension into the inferior wall of the left main bronchus. A large draining vein was seen extending from the mass into the left inferior pulmonary vein (Fig. 3). No definite arterial feeders were noted to this mass, which was confirmed on

A. Robert et al. / Clinical Imaging 38 (2014) 218–220

Fig. 1. (a) Axial contrast enhanced CT image at the level of aortic root shows a heterogenous mass in the anterior mediastinum with phleboliths (arrowheads) within. Also noted is a draining vein, which drains into a dilated SVC (arrow). (b) Coronal reformatted image shows the craniocaudal extent of this lesion extending down to the cardiophrenic angle. Again noted are dilated tortuous veins (arrow).

Fig. 2. Gross appearance of the anterior mediastinal mass (arrow).

Fig. 3. (a) Axial HASTE MRI image at the level of subcarinal region shows a hyperintense infiltrating mass in the middle mediastinum extending into the left hilar regions (arrow). Draining veins are also seen (arrowhead). (b) Coronal T2 weighted MRI image shows the craniocaudal extent of the mass, which is hyperintense in signal intensity. Also seen is the obliquely coursing large draining vein as it empties into the left inferior pulmonary vein (arrow). (c) Coronal reformatted image of MR angiogram depicts the large draining vein emptying into the left inferior pulmonary vein (arrow). (d) Axial T1-weighted post-gadolinium spin echo MR image shows heterogenous enhancement of this mass (arrow). HASTE, half Fourier acquisition single shot turbo spin echo.

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Table 1 ISSVA/Mulliken classification 1996 Vascular tumors

Infantile hemangioma Congenital hemangioma Tufted angioma Kaposiform hemangioendothelioma Hemangiopericytoma Pyogenic granuloma Spindle-cell hemangioendothelioma

Vascular malformations Simple

Combined

Capillary Lymphatic Venous Arterial

AVF, AVM CVM, CLVM LVM, CAVM CLAVM

AVF, arteriovenous fistula; AVM, arteriovenous malformation; CVM, capillary-venous malformation; CLVM, capillary-lymphatic venous malformation; LVM, lymphaticvenous malformation; CAVM, capillary AVM; CLAVM, capillary-lymphatic AVM.

subsequent conventional arteriogram. This lesion was characterized as a venous malformation. Because the patient was asymptomatic, as well as the infiltrative nature of this mass (extension into the esophageal wall), a decision was made to continue watchful surveillance. The patient reported no new symptoms related to this lesion, and imaging findings remained stable for three years follow up period. 4. Discussion Vascular malformations are structural abnormalities that may contain any combination of capillary, arterial, venous and lymphatic components. Over the years, there has been considerable debate with regards to nomenclature, diagnosis and treatment. Various classifications have been proposed to systematize the nomenclature of these lesions. In one such classification proposed by Mulliken and Glowacki [2], all lesions were classified into two broad categories based on endothelial cell characteristics: hemangiomas and vascular malformations. Another classification by Kaban and Mulliken was based on flow dynamics and classified vascular malformations into low flow and high flow types [3]. The classification by Mulliken and Glowacki was modified in 1996 and the updated International Society for the Study of Vascular Anomalies/Mulliken classified divided vascular birthmarks into vascular tumors and malformations (Table 1) [4]. Mediastinal vascular malformations are rare, most commonly seen in the anterior mediastinum [5–8]. Many of these patients are asymptomatic and are discovered incidentally. If symptomatic, these patients may present with mass effect on neighboring structures. Both of our cases were VVMs. VVM are usually congenital and are distinct from hemangiomas, which may or may not be present at birth. Risk of hemorrhage and rupture exists, although no reports have been noted. CT and MRI are increasingly being used for characterization of these lesions. CT is widely available, offers high spatial resolution, and

clearly demonstrates calcifications and phleboliths (Fig. 1). MRI is less widely available and more time intensive, but offers imaging without ionizing radiation, and excellent contrast resolution. MRI imaging features of VVM include intermediate signal intensity on T1 weighted images and high T2-signal intensity with phleboliths appearing as signal voids. Enhancement depends on the degree of the vascularity, with arteriovenous malformations and fistulas showing more intense enhancement. The typical venous malformations show slow but progressive enhancement. MR based classification of VVM has been proposed based on the size and the margins of the lesions. Increasing lesion grade is associated with poor sclerotherapy treatment response [9]. Conventional angiography remains the investigation of choice in evaluation of vascular malformations and is critical for mapping the arterial feeders and draining veins due to its superior spatial and contrast resolution. With typical imaging characteristics, a diagnosis of vascular malformation can be confidently made obviating the risk of needle biopsy, which can be hazardous in these situations. Management of vascular malformations is challenging. VVM can be treated with surgical resection or percutaneous sclerotherapy [10]. Ethanol is the most widely used sclerosant as it is readily available and user friendly. Lesion morphology and patient preference are the two most important factors whether surgical, interventional or combined techniques are used in treatment. In our cases, conservative management was decided as the preferred option as these patients were asymptomatic.

References [1] Vikkula M, Boon LM, Mulliken JB. Molecular genetics of vascular malformations. Matrix Biol 2001;20(5–6):327–35. [2] Mulliken JB, Glowacki J. Hemangiomas and vascular malformations in infants and children: a classification based on endothelial characteristics. Plast Reconstr Surg 1982;69:412–20. [3] Kaban LB, Mulliken JB. Vascular anomalies of the maxillofacial region. J Oral Maxillofac Surg Mar 1986;44(3):203–13. [4] Garzon MC, Huang JT, Enjolras O, Frieden IJ. Vascular malformations: part I. J Am Acad Dermatol 2007;56(3):353–70 [quiz: 371–4]. [5] Tennyson C, Routledge T, Chambers A, Scarci M. Arteriovenous malformation in the anterior mediastinum. Ann Thorac Surg Jul 2010;90(1):e9-10. [6] Kaplan T, Altuntas B, Ceran S, Sadi Sunam G. Unusual location of arteriovenous malformation; posterior mediastinum. Interact Cardiovasc Thorac Surg Feb 2009;8(2):260–2. [7] Oto O, Metin SK, Guzeloglu M, Gulcu A, Karabay N, Gurel D, et al. A congenital arteriovenous malformation originating from the aorta locating in the posterior mediastinum. Ann Thorac Cardiovasc Surg Aug 20 2012;18(4):387–90. [8] Tsitouridis I, Michaelides M, Pervana S. Posterior mediastinal arteriovenous malformation: report of a case. J Thorac Imaging May 2008;23(2):127–30. [9] Goyal M, Causer PA, Armstrong D. Venous vascular malformations in pediatric patients: comparison of results of alcohol sclerotherapy with proposed MR imaging classification. Radiology Jun 2002;223(3):639–44. [10] Legiehn GM, Heran MK. Venous malformations: classification, development, diagnosis, and interventional radiologic management. Radiol Clin North Am May 2008;46(3):545–97.

Mediastinal venous vascular malformations: report of two cases, with discussion of imaging findings and classification systems.

Mediastinal vascular malformations are interesting group of disorders, which are rarely seen in clinical practice. In this case report, we discuss two...
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