Background: Tumour-infiltrating lymphocyte (TIL)-high breast tumours have a high rate of pathological complete response (pCR) with neoadjuvant chemotherapy. In our routine pathological diagnoses of biopsy specimens from pCR cases, we have observed a high infiltration of plasma cells (PCs). A positive correlation of PCs with favourable patient outcome has recently been reported, but little is known about how PCs contribute to local tumour immunity. Methods: We retrospectively examined biopsy specimens from 146 patients with invasive breast cancer who received neoadjuvant chemotherapy. CD138⁺ PC infiltration was assessed by immunohistochemistry. Multiplexed fluorescent immunohistochemistry (mfIHC) with T and B cell markers was also conducted to elucidate the profile of immune cells. Results: Greater PC infiltration was observed in the pCR group (p = 0.028) and this trend was confirmed in another patient cohort. With mfIHC, we observed significantly more CD8⁺, T-bet⁺CD4⁺, and CD8⁺FOXP3⁺ T cells, total B cells and PCs in pCR cases. Such cases were also characterised by high expression of both PD-1 and PD-L1 on B cells and PCs. In patients with hormone receptor-negative tumours, high PC infiltration was correlated with significantly longer disease-free survival (p = 0.034). Conclusions: We found that higher PC infiltration in biopsy specimens before neoadjuvant chemotherapy was associated with pCR. With mfIHC, we also revealed that the local cytotoxic immune response was clearly enhanced in pCR cases, as was the infiltration of B cells including PCs. Moreover, higher PC levels were correlated with favourable outcomes in hormone receptor-negative breast cancer patients.

Background: In the intraoperative consultation of ovarian tumors, the histological diagnosis of frozen sections (FS) of large tumors is frequently difficult because of the limited number of tumor samples. The application of imprint cytology (IC), in which samples are obtained from wide areas of the tumors, is useful for intraoperative consultation. However, the useful aspects of IC have not been clearly defined. The present study is a detailed comparison of IC and FS that clearly defines the useful aspects of IC.Methods: Fifty‐five cases of ovarian tumors that were examined using both IC and FS were evaluated. The histological diagnoses consisted of benign (16), borderline (6), and malignancy (33). All of the malignant tumors consisted of various types of carcinoma.Results: Benignity and malignancy were accurately diagnosed by both IC and FS. In the borderline group, the diagnostic accuracy of IC was very low (1/6: 16.6%) compared with FS (4/6: 66.6%). The diagnostic accuracy including benign, borderline, and malignant groups was 90.9% (50/55) for IC and 96.3% (53/55) for FS. Concerning the diagnosis of the types of carcinoma, the overall diagnostic accuracy of IC (25/31: 80.6%) was greater than that of FS (21/31: 67.7%), especially for the diagnosis of clear cell carcinoma (IC, 100%; FS, 80%) and mixed carcinoma (IC, 66.6%; FS, 16.6%).Conclusion: The useful aspects of IC in the intraoperative consultation are the diagnosis of benignity or malignancy and the accuracy of diagnosing clear cell carcinoma and mixed carcinoma.

Background In the fine needle aspiration cytology (FNAC) for tumors of the breast, evaluation is frequently difficult because of the thick-layered cell clusters and blood inclusion. Such problems may be resolved by the returned cell block method, but its use has not spread worldwide. Here, we examined the application of the returned cell block method to cases involving difficulty in the evaluation of FNAC to diagnose tumors of the breast. Methods In Juntendo University Nerima Hospital, there were 22 cases which were difficult to diagnose by Papanicolaou stain only, and they underwent additional examination using the returned cell block method (cell block from a Papanicolaou staining smear on a glass slide). The usefulness of the returned cell block method in these cases was examined. Results Among the 22 cases, a correct diagnosis was facilitated in 20 cases using the returned cell block method. In 16 of the 20 cases, the difficulty in FNAC was because of thick-layered cell clusters (12 cases) and blood inclusion (four cases). Among the 12 cases with difficulty because of the thick-layered cell clusters, 10 cases (83%) comprised intraductal papilloma (six cases) and intraductal papillary carcinoma (four cases). Papilloma and papillary carcinoma were correctly diagnosed by the addition of histological images and immunostaining of myoepithelial cells using the returned cell block method. Conclusion The application of the returned cell block method is useful for precise evaluation of the cytological diagnosis of tumors of the breast, especially papillary lesions. Diagn. Cytopathol. 2016;44:505–511. © 2016 The Authors Diagnostic Cytopathology Published by Wiley Periodicals, Inc.