Category: Abdominal Imaging, Region: Abdomen-Vessels, Plane: Axial
Summary: A case report of a 72-year-old female patient presenting with right-sided abdominal pain and back pain, on whom initial abdominal ultrasound revealed a hepatic mass. With the aid of subsequent CT imaging and biopsy, a leiomyosarcoma of the inferior vena cava was found. Palliative chemo-radiotherapy was offered to the patient. The literature on leiomyosarcoma, its presentation in the inferior vena cava and the use of diagnostic imaging has been discussed. Case report: A 72-year-old lady with a background of diet-controlled diabetes and hypertension, presented with 4 months history of non-specific right-sided abdominal and back pain, which had not resolved with simple analgesia. On examination, she was found to have marked lower limb oedema extending up to the middle of the torso. Abdominal examination revealed old mid line laparotomy scar with palpable hepatomegaly, 1cm below the sub-costal margin. There was no lymphadenopathy. Cardiovascular examination was normal and the jugular venous pressure (JVP) was not elevated. An initial ultrasound scan revealed a mass in the right lobe of the liver (Figure 1). A CT scan revealed a heterogeneous soft tissue tumour originating from the inferior vena cava (IVC). The mass was centered on the intra-hepatic IVC measuring 46 x 61 x 122 mm extending down to the infra-hepatic IVC (Figure 2a). The IVC lumen was nearly fully occluded by the tumour. The radiological appearances were typical of an IVC leiomyosarcoma. The middle and right hepatic veins were occluded with radiological features in the right lobe of the liver similar to appearances of Budd Chiari syndrome (Figure 2b). CT imaging also demonstrated a nodule in segment 7 of the liver suspicious of a metastatic deposit alongside bilateral pulmonary metastasis and small volume ascites. The liver function tests and tumor markers including alpha-fetoprotein, carcinoembryonic antigen and CA19-9 were normal. A transhepatic ultrasound-guided biopsy was performed. Histology showed a moderately pleomorphic spindle cell neoplasm with typical features of smooth muscle histogenesis3. Positive immunohistochemical staining for smooth muscle actin and desmin confirmed a diagnosis of a leiomyosarcoma. Following discussion at the regional sarcoma MDT meeting a decision to treat the patient with palliative chemo-radiotherapy was made. Discussion: Leiomyosarcoma (LMS) is a type of soft tissue sarcoma that originates from smooth muscle cells and considered the malignant counterpart of a leiomyoma. The most common specific subtypes of soft tissue sarcoma registered in the UK between 2008-2010 were leiomyosarcoma (18%), fibroblastic sarcoma (14%) and liposarcoma (13%). According to data published by Cancer Research UK1, 20% of sarcomas were recorded as “sarcoma NOS” a group which includes tumours diagnosed as undifferentiated sarcoma and those without a specific subtype named. Two thirds of the cases of leiomyosarcoma were found in the female population, with the incidence peaking in the elderly (70-79 aged) in both genders. Between 1996-1998 there were 749 cases of Leiomyosaroma in the UK, whereas between 2008- 2010 the number of cases declined to 604. This 24% decrease probably reflects narrowing of the subtype definition with the recognition around this time of gastro-intestinal stromal tumours (GISTs) as a specific and separate entity. The aetiology of Leiomyosarcoma is not known, but studies have indicated that there are genetic and environmental risk factors. Patients with Li Fraumeni syndrome are at greater risk of developing a leiomyosarcoma. Around 13% children who have retinoblastoma develop a soft tissue sarcoma within 50 years. Radiotherapy treatment is thought to cause 3% of leiomyosarcomas, usually 10-15 years after initial therapy. Environmental exposure to chemicals such as; vinyl chloride, dioxins and chlorophenols have also been linked2. The risk of leiomyosarcoma along with other types of soft tissue sarcomas may be elevated in people with HIV, though this appears to be causatively linked to Epstein-Barr virus infection3. Leiomyosarcoma is considered to be the most common primary malignancy of the IVC, however a fewer than 300 cases have been reported. It is generally slow growing tumour and remains confined to the vessel wall in the early stages and patients can be asymptomatic for a long time prior to diagnosis. The presentation can vary dependent on the site of the tumour. Tumors that arise in the IVC infra-hepatically present with lower extremity oedema and vague abdominal pain. If the tumor developed in the supra-hepatic segment of the IVC, Budd-Chiari syndrome can develop as a result of compression of the hepatic veins causing, hepatomegaly, jaundice, and ascites. Kieffer et al have reported leiomyosarcomas of the inferior vena cava in one of the largest series of cases in 2006. Their results were in agreement with previous case reviews. Their main findings were: a female predilection, mean age in the sixth decile, abdominal pain as the presenting symptom, inconsistent oedema of the lower limbs, and potential for development of Budd-Chiari syndrome and intracardiac extension. They also studied the segment of the IVC involved in each case and found that segment II (interrenal and retrohepatic segment) was the most commonly involved segment and this raises challenges for operative treatment5. CT is the primary modality for assessment of suspected leiomyosarcoma and metastatic disease. Multiplanar capabilities of MRI are particularly useful to distinguish the precise tumour site and involvement of adjacent tissues. Gadolinium is used to assess tumour margins, vascularity and vessel involvement with MRI6. Tumours involving the large veins can often be intraluminal, extraluminal or a combination of both. These well-defined lesions may expand the vessel lumen and appear isointense to muscle on T1 and hyperintense on T2 weighted images7. Metastases from leiomyosarcomas are spread haematogenously, with the liver and lungs being the most frequent sites of occurrence. Deep intra-abdominal, retroperitoneal and large vein tumours have the most frequent occurrence of metastases (40–50%). Surveillance imaging varies; O’Sullivan et al report to using contrast enhanced CT scan of the abdomen and pelvis every 6 months for 1 year and annually thereafter. CT thorax is used for surveillance in those with pulmonary metastasis at initial presentation and plain radiographs for those patients without any pulmonary metastasis initially6. Therapeutic procedures or intervention are dependent on the primary location of the tumour and the stage of the malignancy. Optimal treatment for leiomyosarcomas of the IVC could include complete resection of the malignant lesion with preservation of venous return to achieve long-term survival8. Following radical tumor resection the IVC can be managed in various ways including; ligation, primary patch repair and expanded polytetrafluoroethylene tube grafting. IVC ligation and primary patch repair are low risk to severe post-operative oedema9. Extended venous resection was found to have no influence on local recurrence rate nor long-term outcome10. Adjuvant chemoradiotherapy is used in these patients where there is absence of negative margin after resection11. The prognosis for leiomyosarcoma is relatively poor with an overall 5 year survival rate of 35%. Hines et al studied the comparison of the 5 year cumulative survival rates of leiomyosarcomas of varying anatomical origins studying 14 cases. They found that the survival rates were 53% for patients with leiomyosarcoma of the IVC, 47% for those with leiomyosarcoma of the stomach, 43% for those with leiomyosarcoma of the small intestine, 56% for those with leiomyosarcoma of the retroperitoneum, and 65% for those with leiomyosarcoma of the uterus12. Despite having a tumor that originates from the IVC, patients with this tumor type can enjoy reasonably long term survival. Learning points: -Leiomyosarcoma of the inferior vena cava can present with abdominal pain, lower limb oedema and Budd Chiari syndrome. -CT is the primary modality for assessment of this malignancy. -Optimal treatment for leiomyosarcomas of the IVC could include complete resection of the malignant lesion with preservation of venous return to achieve long-term survival. Adjuvant chemo-radiotherapy can be offered to some patients.