Angiomyolipomas (AMLs) represent 0.3% of all renal tumors. The sex ratio is 4 men for 11 women. Most of the time, AMLs are sporadic but in 20% of patients AMLs are associated with Tuberous Sclerosis Complex. Thus they are classically multiple, bilateral, and growing [
A 74-year-old woman with tuberous sclerosis and multiple bilateral AML who had undergone partial polar superior nephrectomy for a renal cell carcinoma in 1990 came after 7 years of surveillance with the evidence of an inferior vena cava thrombus developed from the right renal vein (Figure
Sonography of the IVC thrombus originated from the right renal vein.
Computerized tomography showed multiple renal tumors with spontaneous density inferior to—20 Hounsfield Units (HU) without contrast enhancement. One of these typical AML that was already present in the previous studies was in contact with a homogenous tumor thrombus, well-circumscribed, with the same fatty density and was extended in the inferior vena cava from the right renal vein, below the hepatic veins (Figure
Axial contrast enhanced abdominal CT showing an IVC and renal thrombus with attenuation value—70 HU.
Partial nephrectomy without arterial clamping, lymphadenectomy, or adrenalectomy with thrombectomy was performed. The thrombus was free from the wall of the inferior vena cava and without fibrin clot. The postoperative period revealed to be uneventful. Serum creatinine was 98
Pathologic examination showed a 7-centimeter yellowish tumor, extended with a thrombus presenting the same aspect. It confirmed the diagnosis of AML given by the association of mature adipose tissue, thick-walled blood vessels, and smooth muscle cells. There was no epithelioid contingency.
Clinical and radiological surveillance after 11 years showed no signs of recurrence or metastasis. The renal vein and inferior vena cava were permeable and the renal function was preserved with 78
A MEDLINE review was performed in order to identify all articles entirely published in English and evaluate inferior vena cava extension of AMLs.
All data are presented in Table
References | Age | Gender | TSC | Symptoms | Localization | Size (mm) | Thrombus | PE | Fat on imaging | Management | LND | Epithelioid form | AE | Rec | Follow-up (months) |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1982 Kutcher et al. [ |
16 | f | no | p | Solitary R, upper pole | large | IVC | no | yes | RN, thrombectomy, thoraco-abdominal | no | no | no | nc | nc |
1985 Brantley et al. [ |
45 | f | no | W: p-N/V-H | Solitary R, upper pole, sinus | 90 | IVC | no | yes | RN, thrombectomy | no | no | no | no | 12 |
1986 Rothenberg et al. [ |
62 | f | no | p-IVD | Solitary L, upper pole, sinus | 45 | RA | nc | yes | RN, thrombectomy, middline incision, sternotomy | nc | no | no | no | 36 |
1987 Camunez et al. [ |
22 | f | yes | W: p-H | Multiple R | small | IVC | no | yes | Follow-up | no | nc | no | no | 24 |
1988 Arenson et al. [ |
22 | f | no | p | Multiple R, meRian, sinus | 85 | IVC | no | yes | RN, thrombectomy | pos | yes | no | nc | nc |
1992 Umeyama et al. [ |
75 | f | no | p-H | Solitary R, meRian | 160 | IVC-B | no | yes | NSS and RN, thrombectomy, bi subcostal | no | no | no | no | 4 |
1993 Reiff and Dow [ |
58 | f | no | p-Fever | Solitary R, upper pole, sinus | 120 | IVC | no | yes | RN, thrombectomy, upper transverse, sternotomy | no | no | no | no | 6 |
1993 Honda et al. [ |
58 | f | no | no | Solitary R, upper pole, sinus | small | IVC | no | yes | RN, thrombectomy | no | no | no | nc | nc |
1994 Morris et al. [ |
58 | f | no | p-fever | Solitary R, upper pole | large | IVC | no | yes | RN, thrombectomy, midline, sternotomy | no | nc | no | nc | nc |
1994 Moulin et al. [ |
36 | f | yes | p | Multiple R, upper pole, sinus | large | IVC | no | yes | RN, thrombectomy | nc | no | no | nc | nc |
1995 Leder [ |
30 | f | no | p | Solitary R median | large | IVC | no | yes | RN, thrombectomy | nc | nc | nc | nc | nc |
1995 Hibi et al. [ |
31 | f | no | p-N | Solitary R, lower pole | 90 | IVC | no | yes | RN, thrombectomy | neg | no | no | nc | nc |
1995 Baert et al. [ |
53 | f | no | no | Solitary R, upper pole | 65 | IVC | no | yes | RN and thrombectomy, sub costal | no | no | no | nc | nc |
1996 Cittadini et al. [ |
65 | f | no | no | Multiple L, sinus | 60 | IVC | no | yes | Follow-up | no | no | no | nc | 12 |
67 | h | no | W: p-H | Multiple R, meRian, sinus | 60 | IVC | no | yes | RN, thrombectomy | no | no | no | nc | nc | |
1997 Rubio- |
64 | h | no | no | Solitary R, meRian | 65 | IVC | no | yes | RN, thrombectomy, thoraco abdominal | no | nc | no | nc | nc |
1997 Bernstein et al. [ |
45 | h | no | no | Solitary R, upper pole, sinus | 55 | IVC | no | yes | RN, thrombectomy, thoraco abdominal | no | no | no | no | 16 |
1998 Gotoh et al. [ |
52 | f | no | p | Solitary R | 35 | IVC | no | yes | RN, thrombectomy | no | no | no | no | 10 |
1999 Christiano et al. [ |
42 | h | no | p-loose of weight | Solitary R, lower pole | 205 | IVC | no | no | RN, thrombectomy | pos | yes | no | Meta | 15 |
1999 Ito et al. [ |
40 | f | no | W: p | Multiple R | large | IVC | no | yes | RN, thrombectomy | no | no | no | no | 36 |
2001 Davydov et al. [ |
46 | f | no | p | Solitary R, upper pole | 60 | RA | no | yes | RN, thrombectomy, middline | no | no | PE | nc | nc |
2002 Wilson et al. [ |
69 | f | no | no | Solitary R, upper pole, sinus | 100 | IVC | no | yes | RN, thrombectomy, thoraco abdominal | neg | no | no | nc | nc |
2003 Schips et al. [ |
61 | f | no | p | Solitary L, upper pole | 100 | IVC | no | yes | RN, thrombectomy | no | no | no | no | 36 |
2003 Gam |
56 | f | no | p | Solitary R, sinus | 45 | IVC | no | yes | RN, thrombectomy | no | no | no | no | 12 |
2004 Islam et al. [ |
40 | f | no | no | Solitary R, Riffuse | 110 | IVC | no | yes | RN, thrombectomy | nc | no | nc | nc | nc |
2006 Haritharan et al. [ |
48 | f | no | p-Fever and N/V | Solitary R | 150 | IVC | no | yes | RN, thrombectomy, bi sub costal, sternotomy | no | no | Hemorrhage | nc | nc |
2006 Akcali et al. [ |
55 | f | no | p | Solitary R, no renal tumor | 0 | RA | no | yes | Thombectomy only | no | no | no | nc | nc |
2007 Park et al. [ |
69 | h | no | nc | Solitary R, Riffuse | 130 | IVC | no | yes | RN, thrombectomy | nc | yes | no | Rec + Meta | 12 |
2008 Schade et al. [ |
42 | f | yes | p | Multiple R, upper pole, sinus | 90 | IVC | no | yes | RN, thrombectomy, thoraco abdominal | no | no | no | no | 22 |
2008 Ban et al. [ |
70 | f | no | no | Solitary R, Riffuse | 140 | IVC | yes | yes | RN, thrombectomy | no | no | no | no | 18 |
2008 Moudouni et al. [ |
31 | f | no | p | Multiple L, diffuse | 100 | IVC | no | yes | RN, thrombectomy, lombotomy | pos | yes | no | Rec | 12 |
2009 Sandstrom et al. [ |
31 | h | no | p-Chest pain | Solitary L, upper pole, sinus | 60 | IVC | yes | yes | RN, thrombectomy | no | no | nc | nc | nc |
2009 Christian and Moon [ |
32 | h | no | p | Solitary R, sinus | 140 | IVC | no | yes | RN, thrombectomy, sub costal | no | no | no | no | 2 |
2009 Durand et al. [ |
57 | f | no | no | Multiple R, upper pole, sinus | 45 | IVC | no | yes | RN, thrombectomy | no | no | no | nc | nc |
2010 Tan et al. [ |
44 | h | no | no | Solitary R, sinus | 100 | IVC | no | yes | RN, thrombectomy, bi sub costal | no | no | PE | no | 12 |
2011 Govednik-Horny and Atkins [ |
30 | f | yes | no | Multiple R, lower pole | 80 | IVC | no | yes | Embolization, RN, thrombectomy, lombotomy | no | yes | no | nc | nc |
2011 Lopater et al. [ |
34 | f | no | no | Multiple R | 30 | IVC | no | yes | Thrombectomy first then NSS, sub costal | no | no | no | nc | nc |
2011 Mittal et al. [ |
46 | f | no | p | Solitary R, upper pole, sinus | 70 | IVC | no | yes | RN, thrombectomy, middline | no | no | no | no | 3 |
2013 Grant et al. [ |
22 | f | no | p | Solitary R, Riffuse | 90 | IVC | no | no | RN, thrombectomy | no | yes | PE | nc | nc |
2013 Li et al. [ |
52 | f | no | p | Solitary R, lower pole | 125 | RA | yes | yes | RN, thrombectomy | no | yes | no | no | 6 |
2013 Li et al. [ |
43 | f | no | W: p | Solitary R, upper pole | 55 | IVC | no | yes | Embolization, RN, thrombectomy | no | no | no | no | 3 |
2013 Fernandez-Pello et al. [ |
22 | f | no | no | Solitary R, sinus | 80 | IVC | no | yes | RN, thrombectomy, laparoscopic | no | no | no | no | 3 |
2013 Nouira et al. [ |
34 | f | no | p | Multiple R, Riffuse | 80 | RA | no | yes | RN, thrombectomy, bi sub costal, sternotomy | no | nc | DC sepsis | dc | dc |
2013 A. Riviere | 74 | f | yes | no | Multiple R, meRian | 70 | IVC | no | yes | NSS, thrombectomy, lombotomy | no | no | no | no | 84 |
R: right; N
Venous extension of an AML is rare. We have identified 44 cases of inferior vena cava involvement in the literature including this one.
Medium age was 46.6 years (range 16–75 years). It has a clear female predominance, representing 81.9% of patients. It is concordant to what is observed for common AML [
AMLs were bilateral in 31.9% of patients but were associated with TSC only in 11.4% of them.
Surprisingly, we found one case, reported by Camúñez et al. [
Patients were symptomatic in 67.4% of cases; all were experiencing pain. Gross hematuria was present in 9.3% of patients. Other symptoms were nausea and/or vomiting in 9.1% and fever in 6.8%. Five patients (11.4%) presented a Wunderlich syndrome with acute flank pain and drop of blood pressure or hemoglobin with consistent diagnosis of retroperitoneal hemorrhage due to the rupture of the tumor. TSC was present only in one case of retroperitoneal hemorrhage.
We found that the level thrombus reached the diaphragm in 9 patients (20.5%) and got to the right atrium in 6 patients (13.6%).
In this review, almost all tumors were larger than 4 cm with a mean size of 86.1 mm. Only 2 patients presented a small AML with vena cava thrombus; they had TSC. It has been reported that, in TSC, AMLs are more often symptomatic and have a more aggressive growth pattern [
As it has been previously reported, there is a large majority of right sided AML with inferior vena cava thrombus (88.6% versus 11.4%). There is no clear explanation for it. According to Islam et al., when thrombus is limited to the renal vein there is no difference between left or right side [
We also highlight the special case of AML with epithelioid cells which are now recognized as an individual tumor, different from classical AML [
As reported by Park et al., all reported cases of metastasis of AML in literature were associated with the epithelioid form, expressing the melanocytic marker HMB-45 [
This epithelioid form of AML, characterized by a minor amount of adipose tissues on imaging can mimic the appearance of a clear cell carcinoma [
There are also malignant tumors presenting with evidence of fat on imaging. Hélénon et al. reported several fat-containing renal cell carcinomas [
In addition, classical AML can be wrongly perceived as clear cell carcinoma in case of recent hemorrhage or spindle cell predominance due to the almost undetectable fat component on imaging [
Only symptomatic or larger-than-4-centimeter conventional AML should be considered for intervention. Many studies have correlated the risk of hemorrhage/symptomatic presentation with the size of the tumor [
A nephron sparing approach by either selective embolization or open or laparoscopic/robotic partial nephrectomy is recommended when an intervention is required [
In case of associated venous thrombus, the risk of expansion and cardiopulmonary embolism requires a surgical treatment. Case reported by Shinohara et al. presented with congestive heart failure with a thrombus extended to the right atrium [
In case of radical surgery, the prognosis is satisfying. 91.3% of patients remained free from recurrence or metastasis at a median follow-up of 12 months (mean 16.8 months).
Although the presence of a venous thrombus suggests the malignant nature of the primary tumor, conservative surgery is possible. Cases of nephron sparing surgery for T3a or T3b renal cell carcinoma, whether for imperative indications (solitary kidney or renal failure) or intraoperative discovery of the thrombus, showed outcomes that seem acceptable compared to nonconserving surgery [
Nephron sparing surgery for AML with inferior vena cava extension in tuberous sclerosis is possible depending on the necessity of renal function preservation. It may be proposed as standard surgery for sporadic AML even with inferior vena cava thrombus.
The authors declare that there is no conflict of interests regarding the publication of this paper.