title: An association of peripheral nerve sheath tumors and lipomas.
abstract: We noticed the coexistence of peripheral nerve sheath tumors (PNST) with lipomas within a subgroup of our patients. Given the prevalence of lipomas in the general population, we sought to investigate the extent of coexistence of the two entities aiming at uncovering any plausible association between both.
  
  
  
  A retrospective review of all peripheral nerve sheath tumors (sporadic and syndromic forms) treated by a single surgeon between January 2009 and August 2015 was done. We recorded demographics (i.e., gender, age at diagnosis, imaging information, time to diagnosis) in addition to the method of diagnosis, subtype, number and location of lipomas, if present.
  
  
  
  Over 6 years, 309 patients with PNST were operated/evaluated. These included 141 sporadic (schwannomas, neurofibromas) and 168 syndromic (neurofibromatosis type 1 and 2 and schwannomatosis). We found 32 patients [10.3%, 95% confidence interval (CI) = 7.43%-14.3%] with coexistent lipomas, some of whom also had a family member with lipoma (n = 3). Of these 26 had schwannomas, 3 had neurofibromas and 3 lacked definitive PNST histopathological diagnosis. Fourteen percent of patients with schwannomas and 2.9% of patients with neurofibromas had coexisting lipomas.
  
  
  
  We believe there is an increased association of peripheral nerve tumors and lipomas overall.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Elsherif
authors.affiliation: Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Dusica
authors.initials: D
authors.lastname: Babovic-Vuksanovic
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. spinner.robert@mayo.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Spinner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D006801:Humans; D008067:Lipoma / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D018317:Nerve Sheath Neoplasms / Q000453:epidemiology*; D017253:Neurofibromatoses / Q000453:epidemiology*; D012189:Retrospective Studies
keywords: Lipoma; Mitochondrial mutations; Neurofibromatosis; Peripheral nerve sheath tumors; Schwannoma; Schwannomatosis