Q: What is the most likely diagnosis? show answer

A: Considering a fat-attenuation renal mass, angiomyolipoma is the primary diagnosis. In view of subcapsular collection and surrounding heterogeneity, hemorrhage (also termed Wunderlich syndrome) is also present.

Q: Does presence of fat always means angiomyolipoma? Are there any other fat-containing tumour of kidney? show answer

A: Although this case is typical, without a reasonable differential diagnosis, one should consider a retroperitoneal liposarcoma invading into the kidney. Presence of fat may be occasionally seen in oncocytomas, renal cell carcinomas and Wilms' tumours, although it usually only constitutes a minority of the whole mass.

Q: What typical feature of angiomyolipomas predispose them to spontaneous hemorrhage? show answer

A: Angiomyolipomas typically have large abnormal arterial vessels. Spontaneous hemorrhage is typically seen in larger (>4cm) tumours.

Q: What are the treatment options for this patient? show answer

A: Emergency embolization is the treatment of choice, and should be both life and kidney-saving. Open operative intervention in many cases may necessitate nephrectomy to control bleeding.

Q: What characteristic angiographic features, we see in this case? show answer

A: Dense early arterial network and microaneurysms, are frequently encountered in angiomyolipomas, as in this case. Also, there is lack of arterio-venous shunting. Not the brisk extravasation and pooling of contrast inferiorly.

Q: What does the markedly hyperdense material represent? show answer

A: Successful glue embolization. Note the contrast and air filled cavity which was seen on angiography.

Q: Is there any other future intervention, which should be contemplated, in this case? show answer

A: In such large lesions, with documented hemorrhagic complication, partial nephrectomy should be considered, to prevent any further mishaps.