The renal angiomyolipoma (AML) is a benign tumor characteristically composed of fat,
smooth muscle tissue, and vessels. We collected AMLs from our nephrectomy database,
reclassified them according to their histological appearance, recorded the demographic,
clinical, and pathological parameters, and compared them with oncocytoma (RO) and
renal cell carcinoma (RCC). Immunohistochemistry was ordered in 41 cases. In 2224
nephrectomies, we found 52 AMLs with a 53 mm median size. The mean age was 52.76.
Forty-eight tumors were sporadic, while four were hereditary. The revision resulted
in 31 classic, 13 leiomyoma-like, five lipoma-like, two epithelioid, and one AML with
epithelial cysts. SMA was diffusely positive, except for the epithelioid type, while
MelanA harbored stronger expression than HMB45. AML was more frequent in females and
appeared ten and 7 years earlier than RO and RCC, respectively. The follow-up time
was 7.42 years, and neither tumor-related death nor relapse occurred. AML is rare
in nephrectomies and develops primarily in females in their 50s with an average size
of 50–60 mm at the surgery. The histological appearance in order of frequency is classic,
leiomyoma-like, lipoma-like, epithelioid, and cystic. The MelanA, HMB45, and SMA immunohistochemistry
can support the light-microscopic findings.
