title: Ossifying parosteal lipoma of the thoracic spine: a case report and review of literature.
abstract: BACKGROUND
  Lipomas are derived from the mesodermal germ layer and are frequently encountered in adults, and account for almost 50% of all soft tissue tumors. Lipomas are classified based on their component tissues and location. A rare subtype, ossifying parosteal lipoma, accounts for 0.3% of all lipomas and occurs with intimate association with the underlying periosteum of the adjacent bone. Though lipomas are considered to be benign tumors, ossifying parosteal lipomas can manifest symptoms due to their location and relationship to nearby skeletal tissues. We herewith report the first known case of ossifying parosteal lipoma presenting in the region of the thoracic spine.
  
  
  METHODS
  An otherwise healthy adolescent boy presented with a 3-year history of a slowly enlarging painless thoracic mass. A general physical examination was normal, aside from a painless 10 cm mobile, hard mass along the posterior spine in the region of T4 through T6. Musculoskeletal and neurovascular examinations were normal. An ultrasound suggested a solid, cylindrically shaped mass with diffuse ossification. The mass was resected, and the pathology revealed ossifying parosteal lipoma without evidence of malignancy.
  
  
  CONCLUSIONS
  Ossifying parosteal lipomas are rare, benign soft tissue tumors that should be added to the differential diagnosis of thoracic masses.
authors: Department of Medicine, MedStar Good Samaritan Hospital, Baltimore, MD, USA.|Department of Medicine, MedStar Union Memorial Hospital, Baltimore, MD, USA; zinnfang@gmail.com.
authors: Zin W
authors: ZW
authors: Myint
authors: Department of Medicine, University of Maryland Medical Center Midtown Campus, Baltimore, MD, USA.
authors: Robert D
authors: RD
authors: Chow
authors: Department of Pathology, Loyola University Chicago, Chicago, IL, USA.
authors: Lu
authors: L
authors: Wang
authors: Department of Pathology, Ann & Robert H. Lurie Children's Hospital, Chicago, IL, USA.|Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors: Pauline M
authors: PM
authors: Chou
keywords: ossifying parosteal lipomas; pathology diagnosis; rare benign soft tissue tumors
references: ORL J Otorhinolaryngol Relat Spec. 2000 May-Jun;62(3):170-2
references: 10810265
references: Proc Natl Acad Sci U S A. 1992 Dec 15;89(24):11740-4
references: 1334547
references: Virchows Arch. 1999 Feb;434(2):181-3
references: 10071255
references: J Pediatr Orthop. 2011 Jul-Aug;31(5):e53-6
references: 21654449
references: Oral Oncol. 2001 Jul;37(5):468-70
references: 11377236
references: Br J Radiol. 2008 Aug;81(968):e207-10
references: 18628326
references: Int Arch Med. 2014 Jan 16;7(1):5
references: 24433545
references: Acta Orthop Belg. 2006 Oct;72(5):603-14
references: 17152426
references: Bull Exp Biol Med. 2005 Jul;140(1):122-6
references: 16254637
references: Radiographics. 2004 Sep-Oct;24(5):1433-66
references: 15371618
references: Biochem Biophys Res Commun. 2007 Oct 5;361(4):883-9
references: 17679141
references: J Bone Joint Surg Am. 1964 Apr;46:608-14
references: 14131440
references: Pathology. 1992 Jul;24(3):132-9
references: 1437283
references: Genes Chromosomes Cancer. 1995 Jan;12(1):70-2
references: 7534115
references: J Neurosurg Pediatr. 2010 Mar;5(3):283-4
references: 20192646
references: J Korean Neurosurg Soc. 2013 Dec;54(6):518-20
references: 24527197