title: Assessing normal growth of hepatic hemangiomas during long-term follow-up.
abstract: OBJECTIVE
  Few long-term data describe the natural history of hepatic hemangiomas. Because these lesions are frequently imaged repetitively on studies performed for other indications, health care professionals are commonly confronted with the problem of a growing hemangioma. Because the rate and magnitude of normal growth is not well characterized, it is difficult to recognize lesions growing at an abnormal rate, which may require further evaluation or intervention.
  
  
  OBJECTIVE
  To establish quantitatively the expected growth rate of hepatic hemangiomas and to define a measure of hemangioma growth that could be used clinically to help identify hemangiomas for which growth is more than expected.
  
  
  METHODS
  Retrospective cohort study at an academic hospital tertiary referral center evaluating the growth rate of hepatic hemangiomas on cross-sectional imaging studies during a 10-year period (1997-2007). The mean (SD) follow-up time was 3.7 (1.9) years. The radiology information system was searched in a 10-year period for hemangioma. Patients with hepatic hemangiomas that were 1 cm or larger as seen on cross-sectional imaging (computed tomography or magnetic resonance imaging), and 1 year or more apart were selected. Images with the longest interval between studies were selected for further review. Each study was rereviewed for diagnostic confirmation and to ensure consistency in measurement technique. Lesions were remeasured in 3 dimensions, and volumes were calculated using 3-dimensional software.
  
  
  METHODS
  Primary outcomes include the fraction of hepatic hemangiomas that demonstrated growth during long-term follow-up and the annual growth rate of those lesions.
  
  
  RESULTS
  A total of 163 hemangiomas were identified in 123 patients. The mean (SD) initial size was 3.2 (3.1) cm. During follow-up, 39.3% of hemangiomas grew 5% or more in mean linear dimension. The mean (SD) annual linear growth rate was 0.03 (0.21) cm for all lesions and 0.19 (0.23) cm for those that grew 5% or more. By volume, 44.7% of lesions grew 5% or more. The mean (SD) annual volumetric growth rate was 2.8% (21.0%) for all lesions and 17.7% (22.8%) in those that grew 5% or more. The initial size predicted the growth in linear dimension and volume (P < .001). There was no significant change in growth rate over time, indicating uniform growth (R = 0.00843; P = .92).
  
  
  CONCLUSIONS
  Nearly 40% of hepatic hemangiomas grow over time. Although the overall rate of growth is slow, hemangiomas that exhibit growth do so at a modest rate (2 mm/y in linear dimension and 17.4% per year in volume). Further research is needed to determine how patients with more rapidly growing hemangiomas should be treated.
authors.affiliation: Department of Surgery, Medical College of Wisconsin, Milwaukee.
authors.forename: Hani Y
authors.initials: HY
authors.lastname: Hasan
authors.affiliation: Department of Radiology, School of Medicine and Public Health, University of Wisconsin, Milwaukee.
authors.forename: J Louis
authors.initials: JL
authors.lastname: Hinshaw
authors.affiliation: Department of Radiology, School of Medicine and Public Health, University of Wisconsin, Milwaukee.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Borman
authors.affiliation: Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Milwaukee.
authors.forename: Alison
authors.initials: A
authors.lastname: Gegios
authors.affiliation: Biostatistics Office, Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Milwaukee.
authors.forename: Glen
authors.initials: G
authors.lastname: Leverson
authors.affiliation: Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Milwaukee.
authors.forename: Emily R
authors.initials: ER
authors.lastname: Winslow
mesh_terms: D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006391:Hemangioma / Q000175:diagnosis*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed