Wunderlich Syndrome - Spontaneous Renal Hemorrhage and More

Introduction

Wunderlich syndrome refers to spontaneous renal hemorrhage that is non-traumatic. Non-traumatic renal hemorrhage can be due to pre-existing renal tumors such as renal angiomyolipoma or due to renal artery rupture or intraparenchymal aneurysm. Wunderlich syndrome is different from Mullerian duct anomalies like Herlyn-Werner-Wunderlich syndrome. Wunderlich syndrome can be caused by neoplastic or non-neoplastic renal pathologies.

What Is Wunderlich Syndrome?

The condition, spontaneous renal hemorrhage, was first described by Carl Reinhold August Wunderlich, and Wunderlich syndrome is named after him. Wunderlich syndrome is a condition in which spontaneous non-traumatic renal hemorrhage occurs. The hemorrhage is confined to the subcapsular and perirenal space. Non-traumatic retroperitoneal hemorrhage is a rare, life-threatening condition that can be due to adrenal bleeding, ruptured abdominal aortic aneurysm, coagulation disorders, and renal problems. Wunderlich syndrome is usually caused by angiomyolipoma (non-cancerous tumor) and renal cell carcinoma (cancerous tumor).

What Are the Causes of Wunderlich Syndrome?

Benign and malignant tumors cause Wunderlich syndrome. Angiomyolipoma (non-cancerous tumor) and renal cell carcinoma (cancerous tumor) are the common benign and malignant tumors that cause Wunderlich syndrome. Other causes of Wunderlich syndrome include vasculitis, renal artery aneurysm, rupture of the renal artery, arteriovenous malformation and fistula, venous thrombosis, cystic medial necrosis, segmental arterial mediolysis, polyarteritis nodosa, renal infections, calculus disease, nephritis, coagulation disorders, and cystic rupture. The most common cause of Wunderlich syndrome is angiomyolipoma. Spontaneous bleeding occurs from the pre-existing tumor. Non-traumatic bleeding may be due to arteriovenous malformations or rupture of the renal artery.

What Is Angiomyolipoma?

Angiomyolipoma is a benign hamartoma that is composed of smooth muscle cells, blood vessels, and fatty tissue. It can be sporadic or occurs in association with tuberous sclerosis. Angiomyolipoma is larger and bilateral in patients with tuberous sclerosis and in young patients. Rupture of the angiomyolipoma causes fatal complications. Rupture of the angiomyolipoma causes Wunderlich syndrome. The rupture of angiomyolipoma depends on the size of the tumor. Tumors that are fewer than 4 centimeters usually remain asymptomatic. Tumors larger than 4 centimeters rupture to cause intratumoral or perinephric hemorrhage. Tumors larger than 4 centimeters are associated with an increased risk of intralesional aneurysm formation, which is the possible cause of the rupture. Angiomyolipomas appears as well-circumscribed renal mass on computed tomography (CT) scan.

What Are the Symptoms of Wunderlich Syndrome?

Wunderlich syndrome presents with Lenk’s triad, which includes:

• Acute flank pain.

• Flank mass.

• Hypovolemic shock.

It also causes hematuria and flank tenderness. Based on the volume of blood loss, symptoms of hypovolemic such as muscle cramps, thirst, orthostatic hypertension, abdominal or chest pain, and tachycardia may develop. Hematoma is usually present in the retroperitoneum. Massive acute hemorrhage may occur if the hematoma ruptures Gerota’s fascia and reaches the peritoneum.

What Are the Complications of Wunderlich Syndrome?

Spontaneous renal hemorrhage results in hemorrhagic shock if the bleeding is not prevented. Spontaneous renal hemorrhage elevates blood pressure and results in renal failure subsequently. Renal failure occurs because bleeding accumulates around the kidney and compresses the renal parenchyma for a period of time.

How Is Wunderlich Syndrome Diagnosed?

The diagnosis depends on the history, presenting symptoms, laboratory tests, and radiographic findings. Individuals with Wunderlich syndrome present with classic symptoms such as flank pain, flank tenderness, and hematuria.

• Laboratory Tests - A blood test is performed to evaluate the levels of hemoglobin, complete blood count, blood urea, and serum creatinine.

• Radiographic Imaging - Ultrasound imaging determines the presence of tumors. Color Doppler sonographic imaging helps to identify the presence of intratumoral vascularity in the lesions. It also measures the blood flow of tumors and distinguishes solid tumors, aneurysms, and pseudoaneurysms. Contrast-enhanced ultrasound scan helps to identify active bleeding and pseudoaneurysm formation. This forms a valuable diagnostic tool for detecting th presence of active hemorrhage. Computed tomography (CT) scan determines the presence of angiomyolipoma. Angiomyolipoma appears as a well-circumscribed mass with fatty attenuation of various densities. Fat-poor angiomyolipoma appears as an iso- or hyperattenuating mass with homogeneous enhancement. Epithelioid angiomyolipoma appears as a hyperattenuating mass with homogeneous enhancement or displays a multilocular cystic appearance. Magnetic resonance imaging (MRI) scan is a highly sensitive scan for detecting the presence of angiomyolipoma. It differentiates angiomyolipoma from other renal masses. However, the ability of MRI to determine the vascularity of tumors is limited compared to doppler sonography.

How Is Wunderlich Syndrome Treated?

The treatment for Wunderlich syndrome depends on the severity of the disease. The treatment ranges from monitoring the hematoma to emergency surgical procedures. Therapeutic embolization and nephrectomy are the mainstay treatment for Wunderlich syndrome.

• Surgical Procedures - Surgical procedures such as seminephrectomy or nephrectomy are performed if the patient develops hypovolemic shock. Severe hemorrhage due to vascular causes requires surgical treatment. Robot-assisted partial nephrectomy is performed to treat ruptured angiomyolipoma, which causes retroperitoneal hemorrhage. This is a minimally invasive procedure that preserves the kidneys without compromising the patient’s safety. Most cases of angiomyolipoma do not require any treatment because they remain asymptomatic. It requires treatment if spontaneous hemorrhage occurs due to rupture and causes symptoms.

• Conservative Management - Wunderlich syndrome is conservatively managed if the hemorrhage is minimal, the tumor size is less than four centimeters, and the patient responds to fluid resuscitation. However, bleeding may occur if the lesion cannot morphologically recover. Yearly CT or ultrasound scans should be performed to evaluate the risk of angiomyolipoma rupture.

• Medications - Immunosuppressive agents like Rapamycin and Everolimus effectively inhibit vascular epithelial proliferation and reduces the tumor size in angiomyolipoma. It also reduces the risk of bleeding and rupture.

• Embolization - The choice of embolization and surgery depends on the safety, efficacy, and preservation of the renal structure. Artery embolization is the first-line therapy recommended to control bleeding. It is a minimally invasive procedure that has a low complication rate and preserves the renal structure with less trauma.

Conclusion

Wunderlich syndrome is a rare syndrome that is characterized by spontaneous renal hemorrhage. It is caused by neoplastic and non-neoplastic pathologies. It usually remains asymptomatic, and if symptoms like flank pain and hematuria are present, it should be consulted with the doctor. Various treatment options are available to treat this syndrome. Early diagnosis and treatment help in the management of spontaneous renal hemorrhage.