Praxis Medical Insights

Est. 2024 • Clinical Guidelines Distilled

Made possible by volunteer editors from the University of Calgary & University of Alberta

Last Updated: 8/23/2025

Timing of Seroma Formation After Lumpectomy

General Information

  • Seromas typically develop within the first week following lumpectomy and are one of the most common post-operative complications of breast surgery, according to the American College of Radiology 1

Risk Factors for Seroma Formation

  • The use of acellular dermal matrices in reconstruction cases increases the likelihood of seroma development after breast surgery, as reported by the Ca-A Cancer Journal for Clinicians 2

Clinical Presentation and Detection

  • Seromas may cause breast swelling, asymmetry, or a sensation of fullness, as noted by the Journal of Clinical Oncology 3

Complications of Seromas

  • Large seromas may obscure small residual calcifications on post-operative mammograms, according to the Ca-A Cancer Journal for Clinicians 4

Clinical Implications

  • Seromas may be mistaken for implant rupture or capsular contracture in reconstruction cases, as reported by the Journal of Clinical Oncology 3
  • Hematoma formation produces changes that are difficult to interpret by physical examination and may lead to unnecessary biopsies, as noted by the Ca-A Cancer Journal for Clinicians 4