Lipomas are benign tumors that rarely occur intraluminal in major vessels, which most prevalent in people between 40–60 years. It usually shows no symptoms, but when present it usually shows obstructive symptoms of cardiovascular like congestiveness and edema.5–6 We only found eight cases of SVC lipoma from a literature search in PubMed (Table 1.). Four cases described that patients showed obstructive symptoms. In our case, the patient shows symptoms of periodical arrhythmia which has never been described in other cases even though the one that extended to the right atrium like ours. We assumed that the symptom was due to its position in RA and its gigantic size, therefore we decided not to do any invasive intervention to it. It was confirmed so that the arrhythmia was disappeared after the resection.
Table 1
Author (Year) | Gender/Age | Clinical Presentation | Prediagnostic modalities | Tumor Size | Surgical Approach |
Vinnicombe S (1994)10 | F, 42 y.o | Fatigue, edema face and right hand | CT scan: rounded mass of fat compressing proximal right brachiocephalic vein and SVC Venogram: large lobulated filling defect up to 3.5cm diameter in SVC | 10x5x5cm | not well described |
Thorogood SV (1996)11 | M, 73 y.o | Asymptomatic | CT scan: mass of fat density in SVC and the right braciocephalic vein | not specified | no surgical intervention |
Mordant P. (2010)12 | F, 55 y.o | Asymtompatic | CT scan: intraluminal nonenhancing tumor occluding the distal right subclavian vein, the right brachiocephalic vein, and the SVC up to the right atrium Venogram: total occlusion of the right subclavian and brachiocephalic veins and of the SVC to the level of the azygos vein MRI: fatty intravascular lesion | 9x6cm | median sternotomy with right transclavicular cervicotomy. Transverse venotomy in SVC. En bloc resection, end-to-end anastomosis left innominate vein - SVC |
Bravi MC (2011)4 | M, 63 y.o | Abdominal, right shoulder, and lumbar pain | CT scan: superior vena caval (SVC) filling defect with a subtotal occlusion that extended into the right atrium. MRI: uniform signal drop on fat-suppressed sequences | not specified | not well described |
Tanyeli O (2015)1 | M, 48 y.o | Right arm edema and paresthesia | CT scan and MRI: fat density within SVC | 5x2cm | mini J sternotomy, venotomy |
Concatto NH (2015)13 | M, 58 y.o | Asymptomatic | CT scan: a hypodense elongated lesion with fat density within the superior vena cava MRI: confirmed the fatty nature of the lesion | 11 x 3 cm | not well described |
Wahab A (2017)14 | F, 70 y.o | Asymptomatic | TEE: 2.6x1.6x1.6 cm partially obstructing round, echogenic mass at SVC and RA juction | 2–3 cm | No surgical intervention |
Sundaram N (2020)2 | M, 58 y.o | Asymptomatic | CT scan: intraluminal 5 cm mass in the right innominate vein extending into SVC Venous duplex: large pedunculated 5 cm hyperechoic mass at the junction of the right internal jugular and subclavian veins | 5 cm | median sternotomy with right cervical extension, venotomy in SVC, counter incision in right mid-jugular vein |
Soetisna TW. Et al (2021) | M, 54 y.o | Episodes of SVT and atrial flutter | CT scan: elongated lesion with low density from SVC to RA MRI: big capsulated mass from SVC to RA (fat-rich content) | 15x5x4cm | conventional median sternotomy |
None of those eight cases underwent biopsy before the intervention. There were only a few articles about intravascular lipoma and there was no literature that shows the incidents of intravascular lipoma or liposarcoma. Despite it, there were data about the incidence of lipoma and liposarcoma originated from the heart that shows the rarity of the case (lipoma 0.07%-8.4%; liposarcoma 0.19%-0.5%).7 Nevertheless the rarity of malignancy incidence in the cardiovascular tumor, we still cannot exclude the possibility of malignancy, in this case, due to its size (the biggest lipoma ever been reported in SVC) and the age of the patient. Studies have shown cardiac MRI to be the gold standard diagnostic imaging modality for cardiac lipoma, but it has limited sensitivity that could only distinguish 69% of cases in the setting of well-differentiated liposarcoma.8 Given that malignant tumor originated from cardiovascular required different consideration in treatment options, therefore we still encourage to do the biopsy before intervention to better weigh the risks and benefit of the surgical treatment.
In our case, the cardiac CT and cardiac MRI didn’t specify the origin of the lipoma’s stalk; it was fully described by Elen, et al.9 Given the uncertainty of the tumor origin, we decided to not performed any extensive manipulation due to its probability of increasing surgical technique difficulty and postoperative morbidity or mortality. Two years after, the patient remains to shows no symptoms, and Cardiac MRI also shows no evidence of recurrence of the tumor or the stalk. This evidence certifies that it is not necessary to do any extensive manipulation or other surgical approaches to reach the origin of the stalk since lipoma is a very slow-growing tumor. Nevertheless, we still encourage to do throughout diagnostic approach before the procedure to define the whole mass’ precise location. Extension of cardiac MRI to the cervical region or venography should be considered in any similar cases.
The surgical approach in excising lipoma in SVC should be considered wisely with the support of adequate preoperative diagnostic. Extensive manipulation that could increase surgical technique difficulty or postoperative morbidity and mortality is not necessary since lipoma is a very slow-growing tumor.