Objective: We have previously reported a few sporadic cases of in situ lobular neoplasia (ILN) associated with marked proliferation of CD10 positive basal/myoepithelial cells. Method: Twenty consecutive cases of pure ILN and 9 DCIS were studied. New sections were cut and stained for E-Cadherin and CD10. Results: One out of the 20 cases showed foci of invasive lobular carcinoma in the new cut sections. All 20 ILN cases showed increased proliferation of CD10 positive basal cells, varying from a focal mild increase to a marked proliferation surrounding or mingling with the lobular cells. CD10 positive cell proliferation was least observed in a case of ILN with central necrosis and in foci of ILN seen adjacent to the invasive carcinoma. The invasive tumour cells were CD10 negative. All cases of DCIS had a thin layer of CD10 positive myoepithelial cells, that was incomplete or absent in some foci. Conclusion: Our findings confirm the presence of a unique relationship between excess proliferation of CD10 positive basal cells and ILN; an association which is not seen in DCIS or invasive carcinoma. This is particularly interesting as recent evidence indicates that CD10 is involved in the regulation of mammary stem and 'sphere forming' cells. Objective: Primary neuroendocrine carcinomas (NEC) of the breast are defined by the WHO classification as a group of neoplasms that express neuroendocrine markers in more than 50 % of the cells. These tumors can exhibit different morphologic appearances including solid, nested or alveolar pattern, papillary or mucinous differentiation or conventional ductal structures. The aim of this study is to identify histomorphological features useful in the recognition of this tumors. Method: 160 invasive breast carcinomas were reviewed, none of them previously typified as NEC. 154 were ductal carcinomas (26 grade I, 61 grade II and 66 grade III) and 6 lobullilar carcinomas. In all cases immunohistochemical staining for the neuroendocrine marker synaptophysin was performed. Results: Eight of the 160 cases showed intense immunoreactivity for synaptophysin. All of them were predominantly composed of solid, confluent nests and cords of cells with medium-to high grade nuclear atypia. Two cases showed intense desmoplastic or sclerotic stromal response. A colloid component was identified in another two cases. Conclusion: Due to its morphologic variability, mammary NEC is frequently underrecognized. A predominantly solid pattern of confluent nests and trabeculae associated with a prominent sclerotic stromal response or colloid differentiation should prompt to perform additional immunohistochemical staining in order to exclude neuroendocrine differentiation. Objective: Association between centrosome abnormalities and response to chemotherapy has not been fully elucidated in breast carcinomas (BC). Here we analysed the association between Aurora kinase A (AURKA) and Gamma-tubulin (GT) and response to neoadjuvant chemotherapy (PST) in patients treated with BC. Method: The immunohistochemical expression of AURKA and GT was analysed in 44 core biopsies of BCs taken before administration of PST. AURKA expression was analysed using a modified Allred-like scoring system (intensity and percentage of staining combined). Cells containing one or two centrosomes as determined by GT were considered negative, whereas cells containing more than two centrosomes were regarded as positive. Centrosome amplification was graded in each specimen as follows: negative (0-2 % of cells); weak (2-10 %); moderate (11-20 %); and strong (21 %<). Pathological response rates were assessed using Chevallier's classification. Results: Centrosome amplification was significantly higher in patients achieving complete response when compared with the cases where partial remission or no response was defined (p=0.03), whereas we found no significant correlation between the expression of AURKA protein and response rate to neoadjuvant chemotherapy (p=0.24). Conclusion: BCs showing centrosomal amplification as determined by GT present higher response rates to neoadjuvant chemotherapy, but need further validation.