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Needle tract displacement is a recognized mimicker of invasive ductal carcinoma (IDC). Artifactual displacement of ductal carcinoma in situ (ADDCIS) unassociated with needle tracts may occur secondary to mechanical compression of breast specimens but has not been systematically studied. We identified 16 cases of ADDCIS unassociated with needle tract changes; the majority (75%) were internal referrals to the breast pathology service to rule out IDC, 19% were received as external diagnostic consultations to rule out IDC, and 6% were routine second review cases originally diagnosed as IDC at an outside hospital. The majority (62.5%) of ADDCIS occurred in lumpectomies, whereas 25% occurred in mastectomies and 12.5% in core biopsies. ADDCIS foci ranged from <1 to 5 mm; however, all ADDCIS spanning >4 mm demonstrated a linear pattern of displacement. In all cases, ADDCIS involved mammary stroma in a nonlobular distribution; in half, ADDCIS extended between benign lobules. Immunohistochemistry revealed no myoepithelial cells around the ADDCIS (n=7), adding to the concern for IDC. However, in contrast to most IDC, ADDCIS lacked stromal reaction and showed degenerative, smudged chromatin. None of the 9 patients with significant follow-up (mean, 7 y) developed metastasis. All received further local therapy for DCIS (5 radiation, 4 completion mastectomy); 1 received adjuvant systemic therapy (hormone therapy for contralateral IDC). In conclusion, ADDCIS mimics IDC, particularly given its permeative pattern and absence of myoepithelial cells. ADDCIS is most common in lumpectomies but can occur in mastectomies or core biopsies. Diagnostic clues include smudged nuclear chromatin, lack of stromal response, and linear pattern of displacement in larger lesions. The benign follow-up without systemic therapy supports our view that ADDCIS does not represent true IDC.

Well preserved frozen biospecimens are ideal for evaluating the genome, transcriptome, and proteome. While papers reviewing individual aspects of frozen biospecimens are available, we present a current overview of experimental data regarding procurement, storage, and quality assurance that can inform the handling of frozen biospecimens. Frozen biospecimen degradation can be influenced by factors independent of the collection methodology including tissue type, premortem agonal changes, and warm ischemia time during surgery. Rapid stabilization of tissues by snap freezing immediately can mitigate artifactually altered gene expression and, less appreciated, protein phosphorylation profiles. Collection protocols may be adjusted for specific tissue types as cellular ischemia tolerance varies widely. If data is not available for a particular tissue type, a practical goal is snap freezing within 20min. Tolerance for freeze-thaw events is also tissue type dependent. Tissue storage at -80°C can preserve DNA and protein for years but RNA can show degradation at 5years. For -80°C freezers, aliquots frozen in RNAlater or similar RNA stabilizing solutions are a consideration. It remains unresolved as to whether storage at -150°C provides significant advantages relative to that at -80°C. Histologic quality assurance of tissue biospecimens is typically performed at the time of surgery but should also be conducted on the aliquot to be distributed because of tissue heterogeneity. Biobanking protocols for blood and its components are highly dependent on intended use and multiple collection tube types may be needed. Additional quality assurance testing should be dictated by the anticipated downstream applications., (Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)