==== Front Ann Saudi MedAnn Saudi MedAnnals of Saudi Medicine0256-49470975-4466King Faisal Specialist Hospital and Research Centre 1688563310.5144/0256-4947.2006.310asm-4-310Case ReportWunderlich syndrome following rupture of a renal angiomyolipoma Parameswaran Bimal Khalid Mohammed Malik Neelam From the Salmaniya Medical Complex, Manama, BahrainCorrespondence and reprint requests: Bimal Kumar Parameswaran, MD, Department of Radiology, Salmaniya Medical Complex, Bahrain, Tel: +973-1-728 9008, Fax: +973-1-728 9030, drbimalkumar@rediffmail.comJul-Aug 2006 26 4 310 312 Copyright © 2006, Annals of Saudi Medicine2006This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. ==== Body Wunderlich syndrome refers to spontaneous non-traumatic renal bleeding into the subcapsular and/or perirenal space. The appropriate treatment for this condition depends on the diagnosis of perinephric hemorrhage and the determination of its cause. Radiology therefore plays an important role in the evaluation of patients with this clinical problem. We present the case of a lady who had spontaneous perinephric hemorrhage following rupture of a renal angiomyolipoma (AML) along with a short review of this syndrome. Case A 40-year-old, previously healthy woman was brought to our emergency department in a state of shock following sudden severe left flank pain. On examination, the patient was drowsy, pale, cold and sweating, with a pulse of 120 and no recordable blood pressure. She had severe tenderness in the left flank and resisted further examination. The patient was rapidly resuscitated with IV fluids. Her blood hemoglobin and hematocrit levels, which were 9.7 g/dL and 0.29, respectively, dropped to 6.8 g/dL and 0.19 about 6 hours later. The coagulation profile was normal. A urine test for pregnancy was negative. An ultrasound examination of the abdomen showed a large retroperitoneal lesion of heterogeneous echogenicity displacing the left kidney medially. There was no pelvic mass. A provisional diagnosis of retroperitoneal mass/hemorrhage was made and a CT of the abdomen was deemed necessary for further evaluation. The CT of the abdomen done soon after showed a large left perinephric hematoma displacing the left kidney medially (Figure 1). A hypodense mass of fat density without calcifications was seen in the inter-polar region of the left kidney, poorly marginated from the perinephric hematoma (Figure 2). The CT findings were thus consistent with perinephric hematoma secondary to rupture of a renal AML. The rest of the abdomen was normal. The patient received multiple blood transfusions, which corrected her hemoglobin level. She had no further hemorrhage. The patient later underwent left partial nephrectomy and the renal mass was confirmed to be an AML by histopathology. Follow-up ultrasounds at 3 and 6 months post surgery found no new renal lesions. Discussion The clinical picture of spontaneous renal bleeding confined to the subcapsular and perinephric space in patients with no known underlying cause was first described by Wunderlich in 1856.1 Patients may present with the classic triad of symptoms–acute lumbo-abdominal pain, a palpable mass and general deterioration as hypovolemic shock.2 Causes described for Wunderlich syndrome include benign and malignant renal tumors, vascular lesions like polyarteritis nodosa, renal infections, nephritis, previously undiagnosed hematological conditions and anatomical lesions like cysts and hydronephrosis.2 The commonest cause of spontaneous renal hemorrhage in most series is an AML.3 In our patient the cause for spontaneous perinephric hemorrhage was renal AML. It must be noted that the Wunderlich syndrome is different from Herlyn-Werner-Wunderlich syndrome, which is a malformation characterized by an ipsilateral blind vagina, Gartner duct cyst and ipsilateral renal agenesis.4 AML is a choristoma (benign tumor composed of tissues not normally occurring within the organ of origin) made of fat, smooth muscle and thick-walled blood vessels. The abundant abnormal elastin-poor vascular structures in AML make these lesions prone to aneurysm formation and rupture.5 Eighty percent of AMLs are sporadic, occurring usually in middle-aged women while the remaining 20% are associated with tuberous sclerosis.6 Sporadic AMLs are generally solitary and unilateral, occurring more on the right side. AMLs that occur in association with tuberous sclerosis on the other hand, manifest at a younger age, are likely to be larger and bilateral, and are prone to grow and need surgical treatment.7 Fifteen percent of patients with renal AML present with hemorrhage.8 Our patient had no evidence of tuberous sclerosis. The appropriate treatment for patients with spontaneous perinephric hemorrhage depends on the diagnosis that a hemorrhage has occurred and on the determination of its cause.9 Radiology has an important role in addressing these issues. CT is the method of choice for the demonstration of perirenal hemorrhage, with a sensitivity of 100%.3 However, a CT performed at the time of hemorrhage is only moderately successful in identifying the renal neoplasm causing hemorrhage, with a reported sensitivity being 0.57.3 However, it has been found to identify all cases of Wunderlich’s syndrome due to AML.2 A confident diagnosis of AML can be made by CT by demonstrating the fat content of these lesions.2,3, 8 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 If the initial CT study shows no mass responsible for the hemorrhage, it has been suggested that angiography should be done as it can reveal vascular lesions not shown by CT and also facilitates embolisation.12–14 In cases where angiography fails to identify a cause for spontaneous perinephric hemorrhage, a repeat CT has been recommended to detect the causative lesion in patients who can be stabilized medically, as resorption of the hematoma permits detection of a tumor previously hidden by blood.9,13 Ultrasonography has been found to be only moderately useful in identifying renal hemorrhage and in differentiating the renal mass and clotted blood.2, 3, 8, 15 Biopsy is only rarely useful in the diagnosis of renal AML.8 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. 2, 8 The benign nature of AML supports a partial nephrectomy or other nephron sparing surgery.8 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. 7,13,15 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.16 In conclusion, we have presented a case of Wunderlich syndrome due to rupture of a renal AML, 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 as illustrated in our patient, by revealing the underlying cause as well. Figure 1 CT of the renal region prior to administration of IV contrast shows a heterogeneous attenuation perinephric hematoma displacing the left kidney. Figure 2 Contrast-enhanced CT shows a mass with fat attenuation [thin arrow: −31 HU] in the left renal cortex. ==== Refs References 1 Wunderlich CRA Handbuch der Pathologie und Therapie 2nd ed Stuttgart Ebner & Seubert 1856 2 Albi G Del Campo L Taggaro D Wunderlich’s syndrome: Causes, diagnosis and radiological management Clin Rad 2002 57 840 845 3 Zhang JQ Feilding JR Zou KH Etiology of spontaneous perirenal hemorrhage: A meta-analysis J Urol 2002 167 1593 1596 11912370 4 Dahnert W Obstetrics and gynaecologic disorders:Gartner Duct cyst Dahnert W Radiology Review Manual 5th edition 2003 Lippincort Williams & Williams Philadelphia 1037 5 Eble JN Angiomyolipoma of kidney Semin Diagn Pathol 1998 15 21 40 9503504 6 Logue LG Acker RE Sienko AE Best Cases from the AFIP: Angiomyolipomas in Tuberous Sclerosis RadioGraphics 2003 23 1 241 246 12533658 7 Steiner MS Goldman SM Fishman EK Marshall FF The natural history of renal angiomyolipoma J Urol 1993 150 1782 1786 8230504 8 Nelson CP Sanda MG Contemporary diagnosis and management of renal angiomyolipoma JUrol 2002 168 1315 1325 12352384 9 Sebastia MC Perez-Molina MO Alvarez-Castells A Quiroga S Pallisa E CT evaluation of underlying cause in spontaneous subcapsular and perirenal hemorrhage Eur Radiol 1997 7 686 690 9166566 10 Logue Lloyd G Acker Robin E Sienko Anna E Best Cases from the AFIP: Angiomyolipomas in Tuberous Sclerosis RadioGraphics 2003 23 241 246 12533658 11 Merran S Vieillefond A Peyromaure M Dupuy C Renal angiomyolipoma with calcification: CT-pathology correlation Br J Radiol 2004 77 782 783 15447968 12 Belyille JS Morgenaler A Loughin KR Tumeh SS Spontaneous perinephric and subcapsular renal hemorrhage Radiology 1989 172 733 738 2672096 13 Zagoria RJ Dyer RB Assimos DG Scharling ES Quinn SF Spontaneous perinephric hemorrhage: imaging and management J Urol 1991 145 468 471 1997690 14 Bosniak MA Spontaneous subcapular and perirenal hematomas Radiology 1989 172 601 602 2772165 15 Yip KH Peh WC Tam PC Spontaneous rupture of renal tumours: the role of imaging in diagnosis and management Br J Radiol 1998 71 146 154 9579178 16 Cubillana LP Rosino EH Egea AL Montiel MR Villaplana GH Albacete PM Wunderlich syndrome. 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