Upgrade Rate of Exclusively MRI-Detected Papillomas in Asymptomatic Patients Undergoing Screening or Extent of Disease Examinations.

Objective: To determine the upgrade rate of exclusively MRI-detected benign papillomas in asymptomatic high-risk patients, patients with a history of cancer, or patients with known malignancy.

Methods: This IRB-approved retrospective study reviewed all breast MRI-guided biopsies yielding papilloma on pathology for all asymptomatic patients undergoing breast MRI for high-risk screening, newly diagnosed breast cancer, or a personal history of breast cancer. All cases were followed by excision or 2-year imaging follow-up. The upgrade rate was determined. Fisher's exact test was used to determine the significance of associated factors, including lesion type, lesion size, and ipsilateral malignancy.

Results: Of the 258 MRI-guided biopsies, 117 met the inclusion criteria. A 4% (5/117) upgrade rate was found with a 3% (4/117) upgrade rate to ductal carcinoma in situ (DCIS) and a 1% (1/117) upgrade rate to invasive malignancy for all identified papillomas. When evaluating all papillomas, the only associated feature identified to be statically significant for risk of upgrade was ipsilateral malignancy with a 60% (3/5) upgrade rate with a P-value of .0057. When separately evaluating benign papillomas only by excluding those with atypia or additional high-risk lesion at biopsy, a 4% (3/80) upgrade rate to DCIS was found. There was no upgrade to invasive malignancy.

Conclusion: Upgrade of MRI-detected papillomas in asymptomatic high-risk patients, patients with a history of cancer, or patients with known malignancy is 4% in this population, which suggests these lesions may warrant surgical excision.