title: Developing asymmetric breast tissue.
abstract: OBJECTIVE
  To show that benign asymmetric breast tissue detected mammographically may increase over time.
  
  
  METHODS
  Serial mammograms obtained in 21 women with negative physical examination results and mammographically detected developing asymmetric breast tissue were reviewed, and findings were correlated with results of biopsy (n = 16), ultrasonography (US) (n = 8), and contrast material-enhanced magnetic resonance (MR) imaging (n = 3). Five patients who did not undergo biopsy were followed up for 13-84 months. Thirteen of 16 biopsy specimens were reviewed.
  
  
  RESULTS
  At the time of mammographic change, 12 patients without baseline asymmetric tissue had a mean age of 41.7 years and a mean size of asymmetric tissue of 2.4 cm. The mean age of nine patients with baseline asymmetric tissue was 46.9 years. In eight patients, the mean size increase was 2.5 cm. One patient showed increased tissue density but stable size. All US and MR images were negative. Pseudoangiomatous stromal hyperplasia was present in all 13 biopsy specimens reviewed and extensive in 12. No malignancies have been reported in five of the followed-up patients, and two have had continued enlargement of asymmetric tissue.
  
  
  CONCLUSIONS
  Pseudoangiomatous stromal hyperplasia is a common histopathologic finding in developing asymmetric breast tissue. Follow-up, rather than biopsy, is a management option if benign imaging and clinical criteria are met.
authors: Department of Radiology, Jefferson Medical College, Philadelphia, PA, USA.
authors: C W
authors: CW
authors: Piccoli
authors: S A
authors: SA
authors: Feig
authors: J P
authors: JP
authors: Palazzo
mesh_terms: D000328:Adult; D001706:Biopsy; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D006801:Humans; D006965:Hyperplasia; D008279:Magnetic Resonance Imaging; D008327:Mammography; D016217:Ultrasonography, Mammary
chemical_list: D003287:Contrast Media