ANGIOMYOLIPOMA WITH INTRATUMORAL PSUEDOANEURYSM AND HAEMORRHAGE
A 33 year old female patient presented with right flank pain for 2 days with no history of hematuria. CECT abdomen was done
3D volume reconstructed images shows the pseudo aneurysm in the right renal area
Coronal image shows the same findings in mid pole of right kidney. |
Sagittal images of the same
USG shows a heterogenous right renal inter polar mass with hyperechoic components and a round hypoechoic intratumoral area.
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The round intratumoral area shows bidirectional colour flow (red and blue) signal on colour Doppler study, suggestive of pseudo-aneurysm |
Renal angiomyolipoma
It’s is the most common solid tumor of the kidney. There is excess growth of smooth muscles and thick walled blood vessels and mature fat. They are classified under perivascular epitheloid cell proliferation(PEComas). Most commonly associated syndrome is tuberous sclerosis. Multiple bilateral angiomyolipoma s suggest possibility of tuberous sclerosis.
Ultrasonography
Highly echogenic mass (more echogenic than central fat). It may appear as echogenic fat within a tumour or isolated foci of echogenicity. If fat content is less of mixed with blood echogenicity of tumour is reduced and can mimic other tumours of kidney. Posterior shadowing may be seen in angiomyolipoma which can be a differentiating feature with that of renal cell carcinoma.
CT scan
Most accurate in AML. Macroscopic fat can be seen. AML are usually well marginated but do not have a true capsule. They are usually at a margin of the kidney. Intratumoral aneurysm may be present.
MRI
Can also demonstrate fat component. On MRI AMLs have high T1 signal and on fat saturated images a drop in signal is noted. On opposed phase images characteristic Indian ink artefact is seen. Lipid poor AML is usually hypointense on T2 images but RCC s will be T2 hyper intense which will help in differentiating both.
Angiography may demonstrate multiple aneurysms and onion layer appearance.
Management
Annual follow up is recommended for asymptomatic lesions less than 4 cm. For larger lesions due to risk of hemorrhage semiannual evaluation is suggested.
Small solitary lesions less than 2 cm do not require follow up
Larger AMLs, or those that have been symptomatic, can be electively embolized and/or resected with a partial nephrectomy.
Lesions that present with retroperitoneal hemorrhage often require emergency embolization as a life-saving measure.
Differential Diagnosis
- RCC - Macroscopic fat if seen is associated with calcification. Microscopic fat will not show Indian ink artefact in out phase.
- Retroperitoneal liposarcoma - hypovascular
- Adrenal myelolipoma
Confusing case.Good presentation👍
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