is an extremely rare benign tumor described in humans, formed by variable amounts of mature adipose tissue and smooth muscle.
Primary variants of lipoma can be listed as angiolipoma, myolipoma
, fibrolipoma, angiomyolipoma, myelolipoma, chondroid lipoma, chondrolipoma, fusiform cell, and pleomorphic lipoma.
Lipomas are classified into various subtypes according to histopathological features, including fibrolipoma, myxolipoma, chondroid lipoma, and myolipoma
. The literature contains case reports about preperitoneal lipomas and preperitoneal lipoleiomyoma.
In a recent review of 24 cases of renal leiomyoma, 15 were reclassified as angiomyolipoma, myolipoma
, or medullary fibroma .
The differential diagnosis of a nonfunctional adrenal mass includes adrenal schwannoma, adrenal adenoma, adrenocortical carcinoma, adrenal metastasis, adrenal myolipoma
, and neuroblastomas, which include neuroblastoma, ganglioneuroma, and ganglioneuroblastoma.
This can facilitate the diagnosis of angio myolipoma
(AML), as discussed below.