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Mammotome Footprints: Histologic Artefacts in the Era of Stereotactic Vacuum Mammotome Biopsy

Evaluation of breast calcifications and mass lesions is effectively performed by use of vacuum-assisted biopsy, including mammotome and minimally invasive breast biopsy (MIBB). For either biopsy system, the lesion is targeted by a single insertion of the probe, followed by vacuum suction and retrieval of multiple pieces of breast tissue. This technique permits increased tissue sampling and decreases the need for rebiopsy.1 However, new techniques harbor new tissue artefacts, which the surgical pathologist should be aware of. Vacuumassisted biopsies create identifiable histological artefacts, both within the mammotome biopsy tissue and within the subsequent breast excision specimen. Some artefacts merely denote the process of tissue procurement; others may lead to problems in interpretation, with subsequent clinical confusion. A few of these histological artefacts are depicted here. Tissue spherules or whorls are frequently encountered in mammotome biopsies and are secondary to the vacuum and suction process applied to the tissue (Fig. 1). Bovine collagen inserted at the time of mammotome biopsy to mark the sampled area may macroscopically mimic a tumor mass2 and result in overestimation of gross tumor dimensions. A “collagen ball” is observed histologically and should guide the pathologist to re-estimation of tumor size (Fig. 2). Displaced epithelium identified in postmammotome excisional biopsy specimens, a phenomenon also seen secondary to fine needle aspiration and core biopsy,3 may mimic invasive carcinoma (Figs. 3, 4). International Journal of Surgical Pathology Volume 14 Number 3 July 2006 221-222 © 2006 Sage Publications 10.1177/1066896906290167 http://ijsp.sagepub.com hosted at http://online.sagepub.com