Mucocele-Like Lesions of Breast with No or Minimal Epithelial Atypia on Core Biopsy: To Excise or Not?
CV Nguyen, E Resetkova, L Huo. University of Texas M.D. Anderson Cancer Center, Houston, TX
Background: Mucocele-like lesions (MLLs) of breast could be recognized on core biopsy (CB) by presence of mucin-filled ducts with associated extravasated mucin within surrounding parenchyma. Although some recommend surgical excision for radiologically suspicious mass-forming lesions and lesions associated with epithelial atypia on CB, there is limited data regarding whether cases with little or no epithelial atypia should be excised.
Design: Fifty-two breast CB samples between 2000 and 2008 coded as mucin, extravasation, or mucocele were identified in our departmental database. Thirty-five cases were excluded from the study due to diagnosis of concurrent invasive mammary carcinoma (n=13), ductal carcinoma in situ (n=7), or atypical ductal hyperplasia (ADH) bordering on ductal carcinoma in situ (n=2) on the CB samples, history of ipsilateral breast cancer (n=8), no clinical follow-up (n=3), or absence of extravasated mucin (n=2) upon review of the pathology report and clinical history. The remaining 17 MLL cases had minimal to no epithelial atypia on the CB and were the subjects of this study. Slides of CB were evaluated to confirm the diagnosis. Ultrasound-guided (16- or 18-gauge) CB was performed for the 2 mass lesions, and stereotactic-guided (9-gauge) CB was performed for the calcifications with or without a mass in 15 cases. Clinical, radiologic, and pathologic data were reviewed and correlated with results of excision, if performed.
Results: Of 17 MLL cases with no or minimal epithelial atypia on CB, 6 had surgical excision and 11 were monitored by imaging studies. The table illustrates radiologic data and histology of CB samples. Residual MLL was demonstrated in 3 out of 6 excised cases, and minimal epithelial atypia was still present in 2 cases. However, no upgrades to a higher risk lesion were noted upon excision. No significant change in lesion characteristics was observed in cases without excision (median follow-up of 11 months). Of note, 3 of 6 excised cases and 3 of 11 cases in the follow-up group had a history of contralateral breast carcinoma.
Radiologic and histologic characteristics of MLLs on CB
|Imaging data||MLL associated with calcifications||CB diagnosis|
|Procedure, number||Mass||Calcifications||Mass with calcifications||Number (%)||No atypia||Atypia|
|Excision, 6||1||2||3||5 (83)||4||1 minimal ADH; 1 columnar cell lesion w/ atypia|
|Clinical monitoring, 11||1||7||3||9 (82)||8||2 minimal ADH; 1 atypical lobular hyperplasia|
Conclusions: Follow-up alone may be appropriate when MLL has no or minimal epithelial atypia on CB.
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 3, Tuesday Afternoon