Mammographic-pathologic correlation of apocrine metaplasia diagnosed using vacuum-assisted stereotactic core-needle biopsy: our 4-year experience.
OBJECTIVE
To determine whether focal apocrine metaplasia of the breast has distinctive mammographic characteristics, we evaluated apocrine metaplasia diagnosed by vacuum-assisted stereotactic core-needle biopsy and correlated mammographic imaging and histopathologic findings.


METHODS
We retrospectively reviewed our institutional database for records of all vacuum-assisted stereotactic core-needle biopsies performed during a 4-year period. Five hundred thirty-eight lesions were biopsied, of which 302 (56%) were benign. Apocrine metaplasia was diagnosed in 37 lesions. In 11 of these 37 lesions, apocrine metaplasia made up more than 50% of the lesion sampled.


RESULTS
On mammography, eight cases (73%) appeared as new or increasing calcifications, and three cases (27%) appeared as new or enlarging equal-density masses (0.6-1.2 cm). Calcifications were heterogeneous in five lesions (63%), amorphous in two (25%), and punctate in one (12%); one heterogeneous cluster of calcifications (12%) also contained milk of calcium. The pattern of calcification distribution was clustered in five lesions (63%), multiple clusters in two (25%), and linear in one (12%). Two masses (67%) were lobular, and one (33%) was round. Two borders (67%) were microlobulated, and one (33%) was circumscribed.


CONCLUSIONS
Apocrine metaplasia is a benign condition commonly associated with other fibrocystic changes. Lesions composed of more than 50% focal apocrine metaplasia are relatively uncommon. A new or enlarging lobular, microlobulated mass or heterogeneous calcification cluster may represent apocrine metaplasia. Because no distinguishing mammographic features are present to require follow-up by imaging, needle biopsy is required for definitive diagnosis.
Kushwaha
Anne C
AC
Division of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Box 57, Houston, TX 77030, USA.
O'Toole
Melissa
M
Sneige
Nour
N
Stelling
Carol B
CB
Dryden
Mark J
MJ
D000328:Adult; D001050:Apocrine Glands / Q000000981:diagnostic imaging* / Q000473:pathology*; D001707:Biopsy, Needle / Q000379:methods*; D001941:Breast Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008327:Mammography; D008679:Metaplasia; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D014618:Vacuum