Open Journal of Urology, 2011, 1, 25-27
doi:10.4236/oju.2011.13007 Published Online August 2011 (http://www.SciRP.org/journal/oju)
Embolisation of Bleeding Renal Angiomyolipoma in
Pregnancy
Chin Hong Lim, David Mulvin
Department of Urology, St. Vincent’s University Hospital, Dublin, Ireland
Received May 10, 201 1; revised June 18, 2011; accepted June 25, 2011
Abstract
Bleeding from renal angiomyolipoma in pregnancy can be catastrophic to both mother and fetus. Selective
arterial embolisation is considered more superior than conventional surgery in these patients. Our case report
exemplifies how a bleeding angiomyolipoma was halted with embolisation in our pregnant patient.
Keywords: Selective Arterial Embolisation, Renal Angiomyolipoma, Pregnancy, Bleeding, Choristoma
1. Introduction
Renal angiomyolipoma (AML) was once considered a
rare tumour with the diagnosis traditionally established
by histology after removal of the renal lesion, it is now
recognised as a relatively common lesion with a broad
range of clinical sequelae that is amenable to different
management options. Recent developments in interven-
tional radiology have provided new tools for diagnosing
and treating this interesting con dition.
2. Case Report
A 32-year-old female gravida 3, para 2 presented with
left flank pain radiating to her left groin at 24 weeks
gestation. Her haemoglobin dropped from 10.7 g/dL on
admission to 6.9 g/dL over 24 hours. On examinations,
the fundus of her uterus palpable consistent with her
gestation and there was fullness and tenderness over her
left renal angle. Investigation revealed haemoglobin of
10.3 g/dL, WCC 11.3 × 109, platelets 186 × 109 and nor-
mal renal function (urea 2.1 µmol/l, creatin ine 49 µmol/l).
Her ultrasound show ed 7 × 8 cm echogenic lesion in her
left kidney with hyperechoic component suggestive of
angiomyolipoma (Figure 1). She was haemodynamically
stable after transfusion of 2 units of red cells. On day 3
post-admission, she developed pain and her Hb dropped
from 10.7 g/dL to 8.6 g/dL. She underwent urgent MRI.
But because of her claustrophobia, only T1 axial se-
quences and localisers could be obtained. This confirms
the presence of a large (approximately 12 cm) left-sided
abdominal mass with a high signal within it consistent
with fat or blood (Figure 2). The overall MR appear-
ances are entirely consistent with the presumptive clini-
cal diagnosis of a bleed into a left renal tumour, most
likely angiomyolipoma. It was elected to proceed to em-
bolisatio n of bleeding angi omyolipoma.
An initial aortogram was performed via the left femo-
ral artery to assess the number and location of left renal
artery. Selective renal arteriography was then used to
delineate the vascular anatomy of the target tumour . The
feeding vessel was then selectively catheterised with
microcatheter (Figure 3(a)). Embolisation was per-
formed with combination of microspheres (300 - 500
microns) (Terumo Europe N.V.) and coil (3 mm) (man-
ufactured by William Cook Europe) positioned in ac-
tively bleeding vessel. Post-embolisation film showed
excellent result. (Figure 3( b)).
Following the procedure, the patient complained of
left sided pleuritic chest pain and palpitations. Spiral CT
revealed no evidence of pulmonary embolism and her
symptoms settled with simple oral analgesia. Her repeat
Haemoglobin for the next 5 days was stable and she was
discharged on day 6 post-embolisati o n.
The proceeding pregnancy was completely uneventful
and at 40 weeks she gave birth by elective caesarean
section to a normal female infant weighting 3000 g.
There were no further complications during the preg-
nancy or in the post-p artum period.
She was reviewed on outpatient clinic 8 weeks post
partum complaint of ongoing left flank pain. CT abdo-
men showed a 10 × 4 × 4 cm collection in left renal bed.
The lesion was not suitab le for re-embolisation and deci-
sion was make to remove the left kidney. She had elective

26 C. H. LIM ET AL.
Figure 1. Ultrasound showed echogenic lesion with hypere-
choic component suggestive of angiomyolipoma.
Figure 2. T1 axial sequences showing a large (approxi-
mately 12 cm) left-sided abdominal mass with a high signal
within it consistent with fat or blood.
(a) (b)
Figure 3. Selective injection into the single renal artery at
the point of its division into two equal-sized branches. Note
the branch feeding the vascular malformation. Post-em-
bolisation showing the stasis of contrast beyond the c oils.
open left nephrectomy and discharged 10 days later.
3. Discussion
The term angiomyolipoma (AML) is attributed to Mor-
gan et al. in 1951 [1], the renal lesion that histological
corresponds to a renal AML was first described by Gra-
witz in 1900 [2]. Angiomyolipoma is composed of adi-
pose tissue, smooth muscle and blood vessels in various
proportions. Angiomyolipoma is composed of different
proportions of adipose tissue, smooth muscle, blood
vessel as a result of abnormal proliferation. Occasionally
it has also been referred to as choristoma due to the
presence of tissue type which did not originated from the
kidney. Irrespective of labels angiomyolipoma is in-
creasingly understood to be a neoplastic but benign
process based on its clinical sequelae and molecular
characteristics.
AML appears in two distinctive settings , as part of the
tuberous sclerosis complex (TSC) and sporadically in
individuals who otherwise have no clinical features of
that entity. In the former group, these tumours are often
bilateral, have multicentric foci and tend to bleed more
often than sporadic variant [3,4]. Steiner et al. demon-
strated that this group have worse outcome with faster
growth rates (67% versus 21%) and earlier need for op-
erating intervention (50% versus 28%) [5 ].
The sporadic type AML is in comparison a slower
growing neoplasm with better outcome. However, even
in this form, female or pregnant patients tended to have a
more complicated AML. In fact, L’Hostis et al. and
Henske at al discovered the presence of progesterone and
oestrogen receptors in these tumours [6,7].
Although most AMLs are small and asymptomatic,
some authors suggested that up to 80% of patients when
tumour size reaches 4 cm or greater, half of them present
with abdominal or flank pain and 10% - 20% with hae-
maturia or palpable mass [8]. The tendency to rupture has
been attributed to the weak, elastin poor vascular struc-
tures in the tumour. This presentation appears to occur
during the physiological changes of pregnancy.
Treatment options for AML include total or partial
nephrectomy, cryoablation, radiofrequency ablation and
transcatheter selective arterial embolisation. Since the
first report of angiographic AML embolisation, this
technique has become common for managing this entity.
The principal advantages of selective embolisation for
AML include the preservation of functional renal paren-
chyma, ability to embolise bleeding vessels selectively
and circumvention of need for a surgical excision or
general anaesthesia. The most common indication for
embolisation has been acute haemorrhage due to sponta-
neous tumour rupture. Other indications include symp-
tomatic tumour in patients who are poor operative can-
didates or have limited renal reserve. With our patient,

C. H. LIM ET AL.
27
because of her pregnancy, operative intervention would
be best avoided. Hence, we chose embolisation of the
tumour to control the bleed ing while waiting for the ges-
tation to finish.
In the literature, complications after embolisation were
reported in 10% of cases, the most common being ab-
scess formation (5%) and pleural effusion (3%). A single
death from respiratory failure was reported in a patient
with severe pre-existing lung disease. 85% of patients
experienced a post-embolisation syndrome of flank pain,
fever, leukocytosis and nausea attributable to inflamma-
tory mediators. Treatment is supportive with antipyretics,
antiemetics and analgesics and most patients recover in 2
to 5 days [9].
Spontaneous renal haemorrhage during pregnancy is
uncommon but consequences may be catastrophic. The
first case of AML associated with bleeding in pregnancy
was reported in 1964. A total of 16 cases have since been
published with only two associated with tuberou s sclero-
sis. 12 of the 16 cases required su rgical intervention dur-
ing the pregnancy while the other 4 had embolisation.
One woman had embolisation prior to becoming preg-
nant but had two episodes of rebleeding during preg-
nancy. She was managed conservatively and completed
the pregnancy without any complications. The other
women completed a normal pregnancy and had emboli-
sation 7 days post-partum. Two patients had embolisa-
tion during pregnancy at 28 and 12 weeks respectively
[10].
In conclusion, selective arterial embolisation is an at-
tractive alternative to surgical intervention for spontane-
ous haemorrhage from AML during pregnancy. As with
patient, ongoing symptoms and high possibility of reb-
leeding (large tumour), nephrectomy may be required
post partum.
4. References
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