CASE 13880 Published on 30.08.2016

Primary leiomyosarcoma of inferior vena cava

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Subbarao Chandana

Leighton Hospital,
Mid Cheshire Hospitals NHS foundation Trust;
Middlewich Road
CW1 4QJ Crewe;
Email:subbarao_cv@yahoo.co.uk
Patient

58 years, female

Categories
Area of Interest Abdomen, Veins / Vena cava, Abdominal wall, Vascular ; Imaging Technique CT, Ultrasound
Clinical History
Weight loss. Back pain. Prominent abdominal veins. Palpable mass in epigastrium.
Imaging Findings
Ultrasound revealed an oval, lobulated hypoechoic mass expanding the inferior vena cava (IVC) with internal vascularity on colour Doppler. It measures 10cm x 5.5cm, involves the suprarenal and intrahepatic IVC and extends into the right renal vein. The hepatic veins are not involved.

Contrast-enhanced arterial phase CT demonstrated a large, lobulated, hypervascular retroperitoneal mass to the right of the abdominal aorta, inseparable from the IVC with extraluminal extension anteriorly. On delayed venous phase, the mass showed inhomogeneous enhancement with some areas of necrosis. No calcification or fatty elements are seen in the mass. Inferiorly it extends into the right renal vein. No mass is seen in the right kidney.

A non-enhancing filling defect suggestive of a thrombus is also seen in the distal IVC. Dilated collateral veins are seen on anterior abdominal wall and around the liver, bypassing the obstructed segment of IVC. No evidence of intra-abdominal lymphadenopathy or other retroperitoneal mass.
Discussion
Malignant involvement of IVC is rare and may be due to primary leiomyosarcoma or tumour thrombus. Tumour thrombus is more common.

Primary leiomyosarcoma of IVC arises from smooth muscle in the media of IVC. It is the commonest primary tumour of IVC with strong predilection for 40-60 year old women [1] (male to female ratio of 1:5).

Clinical features and resectability depend on the segment of IVC involved - lower segment below renal veins, middle segment between renal and hepatic veins or upper segment above hepatic veins. Leiomyosarcoma of IVC most commonly involves the middle third. The tumour starts in the wall and as it grows, it can be predominantly intraluminal (33%) or predominantly extraluminal (66%) [2]. Extraluminal tumours may invade adjacent structures. Haematogenous metastasis to liver, lungs and brain is common. Lymphatic spread to local nodes may occur in late stages [3].

Clinical presentation is non-specific with weight loss, malaise, abdominal and back pain. Infrarenal leiomyosarcomas are often slow growing, develop adequate collateral circulation and cause venous obstruction only late in the disease. Tumours of middle segment may involve the renal veins and present with nephrotic syndrome. Tumours of upper segment may involve the hepatic veins and present with varying degrees of Budd-Chiari sydrome [4].

Accurate identification of superior extent of tumour is vital for surgical planning and management. Ultrasound, CT and MRI demonstrate a lobulated enhancing mass expanding or encasing the IVC with or without involvement of renal / hepatic veins. Ultrasound can often accurately localize it to the IVC. CT in arterial and delayed venous phase is important to demonstrate hypervascularity and extent of tumour. Histological diagnosis is possible with ultrasound or CT-guided biopsy.

Extraluminal IVC leiomyosarcoma should be differentiated from other retroperitoneal tumours and this can sometimes be difficult [5]. Tumour thrombus can be differentiated from bland thrombus by venous expansion, enhancement in the 'mass' and direct continuity between thrombus and tumour in another organ (liver / kidney).

Complete surgical resection with microscopically clear margins is required for cure. Complete resection is possible when lower segment is involved. Tumours involving middle segment need more complicated en bloc resection of IVC, involved renal vein and kidney followed by IVC graft. Upper segment tumours involving right atrium or hepatic veins have the worst prognosis as complete resection is often impossible [6].

Prognosis is poor. Overall 10 year survival is 14% and more than 50% of patients develop recurrent disease.
Differential Diagnosis List
Primary leiomyosarcoma of inferior vena cava
Retroperitoneal sarcoma
Tumour thrombus in right renal vein extending into IVC
Bland thrombus in IVC
Final Diagnosis
Primary leiomyosarcoma of inferior vena cava
Case information
URL: https://www.eurorad.org/case/13880
DOI: 10.1594/EURORAD/CASE.13880
ISSN: 1563-4086
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