Secondary tumours in the breast are rare. Based on literature, an incidence of 0.4-2% is reported. In this population-based study, secondary breast tumours from a 5-year period (2001-2005), not including metastasis from contralateral breast carcinoma, were reviewed (Vestfold County, Norway). A total of 722 patients with breast malignancies were found in this population (89.3% from Vestfold County Hospital). Ten of these, approximately 1.4%, were metastatic tumours, representing four cutaneous melanomas, three pulmonary carcinomas and three malignant lymphomas. The tumours were often solitary, palpable and close to the skin. Radiologically, the lesions mostly resembled primary carcinomas by mammography and ultrasound, which differs from other studies. Comparison with a known primary tumour and use of immunohistochemical profiling is of crucial importance. Melanoma markers (Melan-A, HMB-45, S-100 protein), lung cancer markers (Cytokeratins, TTF1, Chromogranin, Synapthophysin) and lymphoid markers (CD3, CD20) usually help to confirm a secondary breast tumour diagnosis. This approach is especially indicated in diffusely growing tumours with lack of glandular structure and high-grade cytological features, and staining for ER and GCDFP15 may be helpful. Thus, the diagnosis of a breast metastasis may be suspected by careful mammography and ultrasound imaging, although some cases have atypical radiological features, and histological examination might be necessary to ensure a correct diagnosis and appropriate treatment.

Tumor-associated macrophages (TAM) resemble M2 macrophages, promote tumor invasion and show strong expression of CD163 in breast cancer. We here investigated the association between CD163-positive macrophages and vascular invasion, molecular subgroups, mode of detection, and patient outcome. We performed a population-based, retrospective study of invasive breast cancer from the Norwegian Breast Cancer Screening Programme in Vestfold County (2004-2009), including 200 screen-detected and 82 interval cancers. Immunohistochemically CD163-positive macrophages were counted in the most active areas (hotspots) and dichotomized as high (upper quartile) and low counts. Lymphatic vessel involvement (LVI) and blood vessel invasion (BVI) were recorded separately based on immunohistochemical staining (D2-40 and CD31 antibodies). High levels of CD163-positive macrophages were associated with BVI and lymphatic involvement as well as interval cancer detection when compared to screening-detected tumors. In addition, the presence of high CD163+ TAM levels was more often observed in HER2-positive, basal-like and Triple-negative breast cancers and was associated with several features of aggressive tumors. In survival analyses, cases with combined high CD163 counts and BVI showed a significantly reduced recurrence-free survival (RFS) and disease-specific survival (DSS) (P < .001 for both) compared with all other cases. The presence of CD163-positive, tumor-associated macrophages is strongly related to aggressive features of breast cancer such as vessel invasion, detection between screening intervals, non-luminal molecular subgroups and reduced survival.

BackgroundMammography screen-detected breast cancers have a better prognosis than predicted from established prognostic markers. A search for additional features that are characteristic for these tumours and their prognosis is needed to reduce overtreatment, a recognized challenge in breast cancer patient management today. Here, we have investigated the occurrence and importance of tumour elastosis.MethodsWe performed a population based retrospective study of breast cancers detected in the Norwegian Breast Cancer Screening Programme in Vestfold County during 2004–2009. In total, 197 invasive screen-detected cancers and 75 interval cancers in patients aged 50–69 years were compared with regard to standard clinico-pathological parameters and tumour shape, as well as ER, PR, HER2 and Ki67 expression. In particular, the presence of elastotic material in tumours was graded on a 4-tiered scale (score 0–3).ResultsScreen-detected cancers had a significantly higher content of stromal elastosis than interval cancers (p < 0.001). High content of elastosis (score 3) correlated strongly with stellate tumour shape, low histological grade, and ER+/HER2- status. Further, high elastosis score was significantly associated with lower Ki67 expression. In survival analyses, cases with high elastosis demonstrated increased recurrence free (p = 0.03) and disease-specific survival (p = 0.11) compared to cases with low elastosis.ConclusionThere is a strong correlation between the presence of tumour elastosis, stellate tumour shape and mammography detection of breast cancers. To our knowledge, this is the first time elastosis has been studied in relation to breast cancer detection method. Presence of elastosis is associated with low tumour cell proliferation (Ki67) and a good prognosis.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_230

This case describes an infiltrating breast tumour with thyroid transcription factor-1 (TTF-1) positive staining and ductal differentiation in a 72-year-old woman. The presence of ductal carcinoma in situ with positive TTF-1 is a strong indication that this is a primary tumour and not a metastasis from lung.On PET scan and CT follow up there were no other tumours found in this patient. We are not aware of any previously reported TTF-1 positive primary breast carcinoma with ductal differentiation.

Our findings indicate that BVI by tumour cells is strongly associated with aggressive tumour features including a basal-like phenotype, and BVI was an independent prognostic factor in contrast to what was found for LVI.