is a benign renal
neoplasm previously considered to be a hamartoma
, but now known to be neoplastic
. It is composed of variable amounts of fat
, and smooth muscle
elements. The fat density of the tumour on CT
has been regarded to be pathognomonic
, although there are now case reports of renal cell carcinoma types also possessing macroscopic fat.
The lesion is well demarcated and contains mature elements. It occurs in more than 50% of individuals with tuberous sclerosis, often bilaterally. Angiomyolipomata also occur in 40% of women who have a rare, cystic lung disease called lymphangioleiomyomatosis, or LAM.