INTRODUCTION
____
Wunderlich’s syndrome is one of the most feared complications of renal
angiomyolipoma (AML) & should be managed aggressively [1]. Wunderlich’s
syndrome refers to spontaneous non-traumatic renal bleeding into the subcapsular
and/or perirenal space [1,2]. Classic angiomyolipoma is considered to be a benign
mixed mesenchymal tumor that occurs predominantly in the kidney. These tumors
consist of a collection of thick-walled blood vessels, smooth muscle and mature
adipose tissue in varying proportion [2].
The incidence of Wunderlich’s syndrome in the general population is
between 0.07 and 0.3% [2,3]. Approximately 80% of renal AML’s occur
sporadically and 20% are associated with tuberous sclerosis. In the sporadic cases,
these lesions are found usually larger, single and unilateral, with a female
preponderance (approximately 4:1) in the fourth to sixth decade of life. [2].
In symptomatic patients, the classic presentation includes flank or abdominal
pain, a palpable tender mass and gross hematuria (Lenk's triad)[2]. Other
symptoms as nausea, vomiting, fever, anaemia, renal failure and hypotension are
observed less frequently. Three types of hemorrhagic etiology exist, including
Wunderlich's syndrome (spontaneous retroperitoneal hemorrhage of nontraumatic
origin), bleeding or rupture after trauma and rupture during pregnancy (secondary
to a rapid hormonal-related growth). We present a case of Wunderlich's syndrome
in an obese woman with tuberous sclerosis.
CASE REPORT
A 25-year-old unmarried obese female patient, a known case of tuberous
Sclerosis was brought to our emergency department in a state of shock following
sudden severe right flank pain. On examination, the patient was drowsy, pale, cold
and sweating, with a pulse of >100 and low blood pressure. She had severe
tenderness in the right flank with guarding. In addition to this, adenoma sebaceum,
hypomelanotic patches ("ash leaf spots") and shagreen patches [Fig.1] were
detected on her physical examination. The patient was rapidly resuscitated with IV
fluids. Her blood hemoglobin and hematocrit levels were below the normal limits.
The coagulation profile was normal. A urine test for pregnancy was negative. An
initial ultrasound examination of the abdomen revealed angiomyolipomas (AML)
involving both kidneys with large perinephric hematoma on right side and multiple
small hyperechoic lesions of various sizes involving both lobes of the liver [Fig.2].
A provisional diagnosis of AML in both kidneys with right perinephric hematoma
& nonrenal hamartomas was made and a computed tomography (CT) of the
abdomen was deemed necessary for further evaluation.
The contrast enhanced CT of the abdomen done soon after revealed a
hypodense mass of fat density with Hounsefield units (HU) of -50 to -100 without
calcifications in right kidney and large right perinephric hematoma [Fig.4] The
perinephric hematoma is seen
displacing the intestines anteroinferiorly and
crossing the midline with compression over inferior venacava (IVC). The left
kidney also revealed an similar hypodense mass of fat density with HU of -50 to –
100 without calcifications predominantly in the mid and lower pole without
perinephric collection. Liver showed multiple nonenhancing hypodense lesions
involving both lobes of liver. The CT findings were thus consistent with
perinephric hematoma secondary to rupture of a renal AML. Multiple hypodense
lesions seen involving both lobes of liver consistent with biliary hamartomas
[Fig.5]. A diagnosis of Tuberous sclerosis with bilateral renal angiomyolipomas
(AML) with spontaneous rupture of right renal AML (Wunderlich’s syndrome)
was made. CT scan brain of the same patient, revealed multiple subependymal
calcifications [Fig.6] consistent with tuberous sclerosis.
DISCUSSION
Spontaneous nontraumatic bleeding confined to the subcapsular and/or
perinephric space in patients with no known underlying cause was first described
as “spontaneous renal capsule apoplexy” by Carl Reinhold August Wunderlich in
1856 [2,4]. Radiology plays an important role in the evalution of patients with this
clinical problem.
Presentation of this clinical picture may vary greatly depending on the
degree and duration of the bleeding. Commonly acute lumbo-abdominal pain,
nausea, vomiting, hematuria, hemodynamic instability, anemia and hypovolemic
shock are present. Common causes of Wunderlich’s syndrome including benign
and malignant renal neoplasms, vascular disease (vasculitis, renal artery
arteriosclerosis and renal artery aneurism rupture), nephritis, infections,
undiagnosed hematological disorders and anatomical lesions like cysts &
hydronephrosis. Wunderlich’s syndrome is one of the most feared complications of
renal angiomyolipoma and can be fatal if not treated promptly and aggressively.
The commonest cause of spontaneous renal hemorrhage in most series is
angiomyolipoma [1,5]. It has an incidence of about 0.3-3%. Approximately 20%
to 30% of AMLs are found in patients with tuberous sclerosis syndrome (TS), an
autosomal dominant disorder characterized by mental retardation, epilepsy &
adenoma sebaceum, a distinctive skin lesion [7]. Presence of hepatic hamartomas,
which are nonrenal hamartomas lesions, is a minor feature in patients with
tuberous sclerosis. Wunderlich’s syndrome occurs in up to 50% of patients with
tumors larger than 40 mm because of the association with an increased risk of
intralesional aneurysmal formation and, therefore, a greater possibility of rupture
[2,8]. In fact, having abnormal elastin-poor vascular structures, angiomyolipomas
are likely to form aneurysms as they grow and as the blood flow entering them
increases [2]. In contrast, of the 70% to 80% of patients with AML who do not
have TS, a more pronounced female predominance is found & most patients
present later in life during the fifth or sixth decade [1].
Computerized tomography (CT) is the method of choice for the
demonstration of perirenal hemorrhage (sensitivity of 100%) and, if performed
during the time of hemorrhage, it has been found to identify all cases of
Wunderlich’s syndrome due to AML [2,5,8,]. However, it has been found to
identify all cases of Wunderlich's syndrome due to AML [8].
A confident
diagnosis of AML can be made by CT by demonstrating the fat content of these
lesions. [5,8,9] Other renal tumors like renal cell carcinoma, liposarcoma,
myolipoma, lipoma, oncocytoma, and Wilm's tumor may also show fat content.
However, it is felt that a renal cortical mass showing predominantly fat attenuation
of less than -20 HU can be diagnosed as an AML, particularly if there is no or little
calcification in the lesion[10,11].
Ultrasonography has been found to be only moderately useful in identifying
renal hemorrhage and in differentiating the renal mass and clotted blood [5,8,9,
13]. Biopsy is only rarely useful in the diagnosis of renal AML [9]. Once a patient
is diagnosed with spontaneous perinephric hemorrhage due to AML, the treatment
options are either surgery or therapeutic embolisation. Embolisation is extremely
useful in the setting of acute hemorrhage due to rupture of renal AML [8,9] the
benign nature of AML supports a partial nephrectomy or other nephron sparing
surgery [9] Surgery also facilitates a pathological diagnosis. However, it is felt that
if the patient can be stabilized medically during the acute phase of spontaneous
perinephric hemorrhage, a nephrectomy can be deferred [12,13]. In a review of the
diagnosis and management of 7 cases of Wunderlich syndrome, Cubillana et al
also found conservative management to be the most acceptable option, unless a
malignant pathology could be demonstrated [14].
In conclusion, we have presented a case of Wunderlich syndrome due to
rupture of a renal AML in a patient with tuberous sclerosis, which is the
commonest cause reported in most series. CT plays an important role in the
management of patients presenting with this syndrome, not only by demonstrating
the perirenal hematoma, but has illustrated in our patient, by revealing the
underlying cause as well.
TEACHING POINT________________________________________
Wunderlich’s syndrome refers to spontaneous non-traumatic renal bleeding into
the subcapsular and/or perirenal space. It is one of the most feared and rare (0.07%
and 0.3% in general population) complications of renal angiomyolipoma.
Wunderlich’s syndrome can present as acute abdomen in patients with tuberous
sclerosis
or
patients
with
isolated
renal
angiomyolipomas.
On
CT
angiomyolipomas are heterogenous density lesions showing high density of 50 to
60 HU (angio component) and fat density (-50 to -100HU) of lipoma component
with perinephric high density collections in case of Wunderlich’s syndrome due to
perinephric hematoma.