Answer for BIR CoW 19 May 2024
Wunderlich syndrome in a tuberous sclerosis patient.
Findings
e/o multiple fairly defined hypo attenuated fat density lesions of varying sizes noted in bilateral kidneys and on contrast administration shows heterogeneous enhancement . Left kidney appears relatively enlarged with extensive fat stranding with thickening of anterior pararenal fascia ,posterior pararenal fascia and lateral conal fascia . e/o multiple ill defined hyperdensities noted within a heterodense collection involving the lower pole of left kidney and in left sub capsular space.on contrast administration , hyperdense areas showed enhancement reflecting active contrast extravasation into the lesion and forms a collection with surrounding hematoma . The above mentioned collection measures 10(cc)x 8.6(ap)x6.6(tr) cm. Delayed images shows relative washout with normal excretion of contrast into left ureter. Visualised bone showed multiple bone islands .
Discussion
Wunderlich syndrome(WS), which was named after Carl Wunderlich, is a rare clinical syndrome characterized by an acute onset of spontaneous renal hemorrhage into the subcapsular, perirenal, and/or pararenal spaces, without a history of antecedent trauma. Patients may present with a multitude of symptoms ranging from nonspecific flank or abdominal pain to serious manifestations such as hypovolemic shock. The classic symptom complex of flank pain, a flank mass, and hypovolemic shock referred to as the Lenk triad is seen in a small subset of patients. Angiomyolipomas and clear cell renal cell carcinomas (RCCs) are the most common benign and malignant neoplasms, respectively, of the kidneys, with a marked propensity to cause WS.A plethora of renal vascular diseases (aneurysms or pseudoaneurysms, arteriovenous malformations or fistulae, renal vein thrombosis, and vasculitis syndromes) account for 20%–30% of cases of WS. ROLE OF IMAGING: USG :a perirenal hematoma appears as an avascular isoechoic to hyperechoic masslike area or fluid collection in the acute stage and a hypoechoic to anechoic fluid collection with possible internal septa and heterogeneity in the subacute and chronic stages that may cause extrinsic compression of the subjacent renal parenchyma . CT : initial modality of choice and is pivotal to diagnosis and management of WS .CT helps in the detection of hemorrhage, allows accurate estimation of its extent, and assists in the differentiation of a hematoma from an underlying mass and the identification of many of the underlying causes of WS. CT angiography may be performed in select patients to identify active contrast material extravasation and a bleeding source. CT angiography: maybe performed in select patients to identify active contrast material extravasation and a bleeding sourcet. Acute hemorrhage appears as a hyperattenuating fluid collection (30–70 HU) on noncontrast CT images. Large hematomas may obscure small renal cysts or masses .The presence of active contrast material extravasation and pseudoaneurysms on postcontrast CT images suggests the possibility of ongoing bleeding that necessitates urgent consultation with an interventional radiologist. MRI: is commonly performed to detect causes of WS in patients in whom the initial or follow-up CT examination did not allow identification of the bleeding source. Signal intensity abnormalities at MRI depend on the stage of blood products. Acute hemorrhage may be variable in signal intensity on T1-weighted MR images, usually appearing isointense to hyperintense. In comparison, subacute hemorrhage demonstrates heterogeneous signal hyperintensity on T1- and T2-weighted MR images due to varying degrees of hemoglobin degradation . Angiomyolipoma: Angiomyolipoma is the most common renal mesenchymal neoplasm and is histologically characterized as a variable distribution of dysmorphic blood vessels, immature smooth muscle cells, and mature adipose tissue . Most angiomyolipomas are sporadic, with a preponderant occurrence in female patients. Approximately 20% of angiomyolipomas are syndromic and occur in patients with tuberous sclerosis complex . Angiomyolipomas that are associated with tuberous sclerosis complex affect younger patients without gender predilection but with a propensity for larger, bilateral, and multifocal tumors . Histologic subtypes of angiomyolipomas are classic or triphasic, epithelioid, or monotypic. Classic angiomyolipomas are benign neoplasms, whereas those of the epithelioid subtype may exhibit a malignant phenotype, with aggressive behavior, including the potential for recurrence and metastasis . At imaging, angiomyolipomas can be classified into fat-rich, fat-poor, and fat-invisible types on the basis of the quantity of identifiable fat at CT or MRI . Fat-rich angiomyolipomas are echogenic on US images, whereas fat-poor and fat-invisible types can demonstrate variable echogenicity. On contrast-enhanced US images, renal angiomyolipomas show relatively reduced enhancement compared with the background renal parenchyma (and more commonly reduced enhancement when compared with that of RCC) . Up to 40% of cases of WS are likely secondary to spontaneous rupture of angiomyolipomas, and 15%–20% of angiomyolipomas manifest with spontaneous perirenal hemorrhage . The incidence of intratumoral bleeding and tumor rupture depends on the size of the tumor and the size of the intratumoral aneurysms . A tumor size of 4 cm or larger and an aneurysm size of 5 mm or larger are associated with a higher risk for rupture. In patients with acute bleeding, transarterial embolization (TAE) is considered the first-line treatment option and can help control bleeding in up to 96% of cases and allow emergency surgery to be avoided . Prophylactic TAE is helpful in decreasing the size and vascularity of large angiomyolipomas and in preventing bleeding. More invasive treatment options such as total nephrectomy can be considered for large angiomyolipomas that are suspected to be malignant or in emergency settings such as profound uncontrolled bleeding.
Reference: https://doi.org/10.1148/rg.220172 Wunderlich Syndrome: Comprehensive Review of Diagnosis and Management
Findings
e/o multiple fairly defined hypo attenuated fat density lesions of varying sizes noted in bilateral kidneys and on contrast administration shows heterogeneous enhancement . Left kidney appears relatively enlarged with extensive fat stranding with thickening of anterior pararenal fascia ,posterior pararenal fascia and lateral conal fascia . e/o multiple ill defined hyperdensities noted within a heterodense collection involving the lower pole of left kidney and in left sub capsular space.on contrast administration , hyperdense areas showed enhancement reflecting active contrast extravasation into the lesion and forms a collection with surrounding hematoma . The above mentioned collection measures 10(cc)x 8.6(ap)x6.6(tr) cm. Delayed images shows relative washout with normal excretion of contrast into left ureter. Visualised bone showed multiple bone islands .
Discussion
Wunderlich syndrome(WS), which was named after Carl Wunderlich, is a rare clinical syndrome characterized by an acute onset of spontaneous renal hemorrhage into the subcapsular, perirenal, and/or pararenal spaces, without a history of antecedent trauma. Patients may present with a multitude of symptoms ranging from nonspecific flank or abdominal pain to serious manifestations such as hypovolemic shock. The classic symptom complex of flank pain, a flank mass, and hypovolemic shock referred to as the Lenk triad is seen in a small subset of patients. Angiomyolipomas and clear cell renal cell carcinomas (RCCs) are the most common benign and malignant neoplasms, respectively, of the kidneys, with a marked propensity to cause WS.A plethora of renal vascular diseases (aneurysms or pseudoaneurysms, arteriovenous malformations or fistulae, renal vein thrombosis, and vasculitis syndromes) account for 20%–30% of cases of WS. ROLE OF IMAGING: USG :a perirenal hematoma appears as an avascular isoechoic to hyperechoic masslike area or fluid collection in the acute stage and a hypoechoic to anechoic fluid collection with possible internal septa and heterogeneity in the subacute and chronic stages that may cause extrinsic compression of the subjacent renal parenchyma . CT : initial modality of choice and is pivotal to diagnosis and management of WS .CT helps in the detection of hemorrhage, allows accurate estimation of its extent, and assists in the differentiation of a hematoma from an underlying mass and the identification of many of the underlying causes of WS. CT angiography may be performed in select patients to identify active contrast material extravasation and a bleeding source. CT angiography: maybe performed in select patients to identify active contrast material extravasation and a bleeding sourcet. Acute hemorrhage appears as a hyperattenuating fluid collection (30–70 HU) on noncontrast CT images. Large hematomas may obscure small renal cysts or masses .The presence of active contrast material extravasation and pseudoaneurysms on postcontrast CT images suggests the possibility of ongoing bleeding that necessitates urgent consultation with an interventional radiologist. MRI: is commonly performed to detect causes of WS in patients in whom the initial or follow-up CT examination did not allow identification of the bleeding source. Signal intensity abnormalities at MRI depend on the stage of blood products. Acute hemorrhage may be variable in signal intensity on T1-weighted MR images, usually appearing isointense to hyperintense. In comparison, subacute hemorrhage demonstrates heterogeneous signal hyperintensity on T1- and T2-weighted MR images due to varying degrees of hemoglobin degradation . Angiomyolipoma: Angiomyolipoma is the most common renal mesenchymal neoplasm and is histologically characterized as a variable distribution of dysmorphic blood vessels, immature smooth muscle cells, and mature adipose tissue . Most angiomyolipomas are sporadic, with a preponderant occurrence in female patients. Approximately 20% of angiomyolipomas are syndromic and occur in patients with tuberous sclerosis complex . Angiomyolipomas that are associated with tuberous sclerosis complex affect younger patients without gender predilection but with a propensity for larger, bilateral, and multifocal tumors . Histologic subtypes of angiomyolipomas are classic or triphasic, epithelioid, or monotypic. Classic angiomyolipomas are benign neoplasms, whereas those of the epithelioid subtype may exhibit a malignant phenotype, with aggressive behavior, including the potential for recurrence and metastasis . At imaging, angiomyolipomas can be classified into fat-rich, fat-poor, and fat-invisible types on the basis of the quantity of identifiable fat at CT or MRI . Fat-rich angiomyolipomas are echogenic on US images, whereas fat-poor and fat-invisible types can demonstrate variable echogenicity. On contrast-enhanced US images, renal angiomyolipomas show relatively reduced enhancement compared with the background renal parenchyma (and more commonly reduced enhancement when compared with that of RCC) . Up to 40% of cases of WS are likely secondary to spontaneous rupture of angiomyolipomas, and 15%–20% of angiomyolipomas manifest with spontaneous perirenal hemorrhage . The incidence of intratumoral bleeding and tumor rupture depends on the size of the tumor and the size of the intratumoral aneurysms . A tumor size of 4 cm or larger and an aneurysm size of 5 mm or larger are associated with a higher risk for rupture. In patients with acute bleeding, transarterial embolization (TAE) is considered the first-line treatment option and can help control bleeding in up to 96% of cases and allow emergency surgery to be avoided . Prophylactic TAE is helpful in decreasing the size and vascularity of large angiomyolipomas and in preventing bleeding. More invasive treatment options such as total nephrectomy can be considered for large angiomyolipomas that are suspected to be malignant or in emergency settings such as profound uncontrolled bleeding.
Reference: https://doi.org/10.1148/rg.220172 Wunderlich Syndrome: Comprehensive Review of Diagnosis and Management
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!