Atypical ductal hyperplasia diagnosed at sonographically guided core needle biopsy: frequency, final surgical outcome, and factors associated with underestimation.

OBJECTIVE: The purposes of this article were to review the mammographic and sonographic features of breast masses yielding atypical ductal hyperplasia (ADH) at sonographically guided biopsy, evaluate the surgical pathology outcome of these lesions, and determine whether clinical or imaging features can be used to predict upgrade to malignancy.
MATERIALS AND METHODS: Among 6325 sonographically guided biopsies (2003- 2010) (14-gauge cores), 56 yielded the diagnosis of ADH (0.9%). Six patients were excluded (lost to follow-up). Fifty lesions were surgically excised in 45 patients. Mammographic and sonographic features were analyzed in consensus by two radiologists using the BI-RADS lexicon.
RESULTS: Forty-five patients (mean age, 56 years; 12 < 50 years; six with synchronous breast carcinoma) had 50 ADH lesions (median size, 0.6 cm). Surgical excision yielded malignancy in 28 cases (56% underestimation rate). Among 42 mammograms (47 lesions), 30 lesions were identified (30/47, 64%) as masses (12/30, 40%), asymmetric densities (10/30, 33%), microcalcifications (4/30, 13%), and architectural distortions (4/30, 13%). Sonographically, most lesions appeared as hypoechoic masses (64%, 30/47) with irregular shape (51%, 24/47), microlobulated margins (49%, 23/47), no posterior acoustic feature (25/47, 53%), abrupt interface (70%, 33/47), and parallel orientation (57%, 27/47). No mammographic and sonographic features were associated with malignant outcome, whereas age less than 50 years (p = 0.03) and synchronous malignancy (p = 0.03) were associated with malignant outcome.
CONCLUSION: ADH diagnosed at sonographically guided 14-gauge core needle biopsy shows a high underestimation rate. Synchronous carcinoma or age less than 50 years is associated with malignant outcome.