pathology station/Renal Angiomyolipoma

Rate :


Renal Angiomyolipoma

  • Benign tumor composed of fat, smooth muscle cells and thick-walled vessels; believe to originate from perivascular epithelioid cells (PEC) (aka, PEComa).
  • Related to other PEComas such as lymphangioleiomyomatosis, "sugar" tumor of lung, cardiac rhabdomyomas, etc.
  • May arise in association with tuberous sclerosis:
    • >50% of patients with TS develop AMLs; <50% of AML has TS.
    • Tend to be asymptomatic, bilateral, small, and multiple.
    • Associated with genetic alteration in TSC1 (chr 9q34) and TSC2 (chr 16p13.3).
  • Abundant fat containing tumor recognizable radiologically.
  • Gross:
  • Range from 1-20 cm (average 9 cm).
  • Golden-yellow appearance is common, but depends on the ratio (>fat looks like lipoma; > smooth muscle looks like leiomyoma) (image A).
  • Usually well-demarcated but not encapsulated.
  • May show local "invasion" or extension into perinephric or sinus fat.
  • Consists of varying amounts of smooth muscle cells, mature fat and thick-walled vessels 
    (image B) and (image C).
  • Vessels abnormal, often hyalinized and thick with eccentric lumen.
  • Smooth muscle cells appear to originate and "radiate" off the vessels (image D).
  • AML with benign epithelial cysts (AMLEC) is a rare variant.
  • Histology:
  • IHC: spindle cells reactive with melanoma marker (HMB-45+, Mart1+) and actin+ thereby distinguishing it from other spindle cell lesions of the kidney.
  • DDX: lipoma (for fat predominant AML), leiomyoma (for smooth muscle predominant AML).
  • Surgical intervention recommended for tumors >4 cm (retroperitoneal hemorrhage is common complication)
  • renal-figureA_Big.jpg




Comments : 4

  • Eldred

    Professor   |     |  
      |   6/21/2020 5:56:02 AM
    Heya i am for the first time here. I found this board and I
    find It really useful & it helped me out much. I hope to
    give something back and help others like you aided me.
  • Wickham

    Professor   |     |  
      |   7/30/2020 3:43:40 PM
    Fabulous, what a web site it is! This webpage gives helpful
    information to us, keep it up. adreamoftrains content hosting
  • Fitzgibbons

    Professor   |     |  
      |   6/28/2020 1:24:54 AM
    My brother recommended I might like this
    blog. He was totally right. This post truly made my day. You can not imagine simply how much time I had spent for this info!

  • Hemming

    Professor   |     |  
      |   6/27/2020 7:42:46 PM
    Way cool! Some extremely valid points! I appreciate you penning this article and also the
    rest of the site is also very good.
  • Leave message

    Your rating:
    Security code