title: An unusual case of left hepatectomy for Focal Nodular Hyperplasia (FNH) linked to the use of Anabolic Androgenic Steroids (AASs).
abstract: BACKGROUND
  Focal Nodular Hyperplasia (FNH) is the second most common benign tumor of the liver. Clinically FNH is asymptomatic and discovered incidentally . The pathogenesis is unclear; FNH is usually asymptomatic. When the tumor is large, it may be painful. Surgery is recommended only in the case of complications such as compression of adjacent organs, lesion progression with tumor size >5cm and presence of symptoms.
  
  
  METHODS
  A 30 years old man, was evaluated during a routine visit, for diffuse abdominal pain and weight loss; Abdominal ultrasound showed no evidence of biliary obstruction but the US shows a hypoechoic, well defined focal lesion in the left liver. For a more accurate diagnosis a Magnetic Resonance detected a focal area about 14×9 cm in diameter, hypointense. Liver biopsy was not done.We could not diagnose it definitively as FNH from the results of imaging studies; so for the size of symptomatic lesion, the undefined diagnosis of FNH ,and due to the great increase in the size of the mass located in the left lobe, during such a short period , the surgery was been recommended.
  
  
  CONCLUSIONS
  FNH is the second most common hepatic lesion, but clinically relevant cases of FNH are rare with a reported prevalence in US studies of 0,03%. In our case the young patient was taking dietary supplements including anabolic androgenic steroids (AASs), carnitine and l-arginine.
  
  
  CONCLUSIONS
  The particularity of our case is the increasing of the lesion in two years in which the patient made use of anabolic steroids. under use of . This could be the explanation for increasing of nodule.
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: angelaromano_ar@libero.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Romano
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: michelegrassia@live.it.
authors.forename: Michele
authors.initials: M
authors.lastname: Grassia
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: g-expo@libero.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Esposito
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: mariannapetrillo@virgilio.it.
authors.forename: Marianna
authors.initials: M
authors.lastname: Petrillo
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: ninopezze@gmail.com.
authors.forename: Modestino
authors.initials: M
authors.lastname: Pezzella
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: damonevic32@gmail.com.
authors.forename: Francesco Maria
authors.initials: FM
authors.lastname: Romano
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: francescodottesposito@gmail.com.
authors.forename: Francesco
authors.initials: F
authors.lastname: Esposito
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: francesco.torelli@unina2.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Torelli
authors.affiliation: Department of general surgery, Second University of Naples, Italy. Electronic address: natale.dimartino@unina2.it.
authors.forename: Natale
authors.initials: N
authors.lastname: Di Martino
keywords: Anabolic androgenic steroids (AASs); Case report; Focal nodular hyperplasia (FNH); Left hepatectomy