Comparison of Confirmed Cytology Smears and Cell Blocks for Epidermal Growth Factor Receptor Mutation Testing in Non-Small Cell Lung Cancer.

INTRODUCTION: Various cytologic specimens have been used to diagnose epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC). However, insufficient samples and lengthy DNA extraction procedures have led to inconsistent diagnostic results. To reduce manipulation losses and improve DNA extraction quality, we provide an improved procedure for DNA extraction from smear samples containing rare tumor cells in NSCLC. PATIENTS AND METHODS: The effectiveness of this new method for DNA extraction and diagnosis was validated in 8 patients with pleural effusion smears and formalin-fixed paraffin-embedded cell blocks, and another with 2 smears. Smear samples with <5% tumor cells were collected, and visible particles were selected for DNA extraction after centrifugation. Qiagen formalin-fixed paraffin-embedded DNA extraction kit (Qiagen) was used for DNA extraction and the procedure was modified. The EGFR mutation analysis in both types of material used the EGFR mutation analysis kit (Therascreen EGFR RGQ PCR) and real-time polymerase chain reaction (Rotor-Gene Q). RESULTS: The DNA extraction amount of the smear was 2.6 to 258.8 ng/µL, and that of the cell block was 1.4 to 139.9 ng/µL. The DNA quantity and purity of DNA extracts isolated from both sample sources were sufficient for subsequent EGFR mutation detection, where mutation rates were similar and diagnostic results were consistent when smears or cell blocks were used. CONCLUSION: This improved method demonstrates that cytology smears can be used as a test material for the detection of EGFR mutations in patients with NSCLC with sparse cells.

An Optimized Melanin Depigmentation Method for Histopathological and Immunohistochemical Staining of Formalin-Fixed Paraffin-Embedded Tissues.

Introduction. The difficulty in diagnosis of severe melanocytic lesions is a problem to be overcome in pathological practice. Melanin bleaching is an effective approach to ameliorate melanin disturbances in severely pigmented lesions. Although various methods for improving melanin pigmentation in immunohistochemical staining have been reported, these depigmentation methods still need to be optimized and standardized. In this study, the coloring efficiency of 3,3'-diaminobenzidine (DAB) and alkaline phosphatase (AP) after melanin depigmentation was compared under the automatic immunohistochemical staining platform. Methods. The applicability of the optimized depigmentation method was validated in 10 formalin-fixed paraffin-embedded (FFPE) blocks of ocular melanoma tissues. Specimens were demelaninized with 10% hydrogen peroxide at 60°C for immunohistochemical staining (Melan-A and SOX10), and tissue chromogenic staining was performed with DAB and AP detection systems, respectively. Results. The optimized depigmentation method including immunohistochemistry (IHC) could be completed in 3 h, effectively preserving cell morphology and immunoreactivity. Among these, the color-rendering effect and contrast of AP are better than DAB. Conclusion. This optimized method can effectively remove melanin and improve the accuracy of IHC staining interpretation. AP staining has better visibility and readability without the interference of residual melanin. The comparison results showed that after melanin depigmentation, the immunohistochemical staining agent was replaced with red AP, which avoided the misjudgment caused by brown DAB when melanin depigmentation was incomplete. This improved method can be applied to future histopathological and immunohistochemical staining of melanin-deposited tissues.

Transferred-tissue Microarray for Fluorescence In Situ Hybridization Test for Human Epidermal Growth Factor Receptor 2 in Breast Cancer.

CONTEXT: Human epidermal growth factor receptor 2 (HER2) status of breast carcinomas is usually determined by immunohistochemical (IHC) staining and, if the IHC results are equivocal, in situ hybridization (ISH). Multiple ISH tests are sometimes required for multiple primary or metastatic tumors. A method for multiplex ISH test on tissues from multiple blocks is helpful in these situations. OBJECT: To evaluate the clinical application of transferred-tissue microarray (TTM) followed by a dual-probe HER2 fluorescence in situ hybridization (FISH). DESIGN: A 3×3 TTM technique was successfully established using 152 invasive mammary carcinoma tissue fragments. To evaluate detection of HER2 positive tumors, this cohort was enriched with tumors with IHC scores of 2 and 3. RESULTS: The HER2 FISH analyses revealed that all transferred-tissue fragments were adequate for determining HER2 amplification. Tissue loss was minimal and had no major adverse effects on interpretation of the test results. Of the 81 tumors with IHC scores of 3, 72 (88.8%) were positive for HER2 FISH. The remaining tumors were negative for HER2 FISH in both TTM and reflex whole tissue section. Finally, FISH results for tumors with IHC scores of 2 were compared between TTM and whole tissue section. Concordance was high in overall positivity/negativity (100%), HER2 copy number (97.5%), and HER2/CEP17 ratio (100%). CONCLUSIONS: This novel technique is a reliable option for performing multiple HER2 FISH tests simultaneously in clinical and research-oriented settings with less tissue damage compared with conventional tissue microarray techniques.

Melanin Bleaching With Warm Hydrogen Peroxide and Integrated Immunohistochemical Analysis: An Automated Platform.

OBJECTIVE: Diagnosing melanocytic lesions is among the most challenging problems in the practice of pathology. The difficulty of physically masking melanin pigment and the similarity of its color to commonly used chromogens often complicate examination of the cytomorphology and immunohistochemical staining results for tumor cells. Melanin bleach can be very helpful for histopathological diagnosis of heavily pigmented melanocytic lesions. Although various depigmentation methods have been reported, no standardized methods have been developed. This study developed a fully automated platform that incorporates hydrogen peroxide-based melanin depigmentation in an automated immunohistochemical analysis. METHODS AND MATERIALS: The utility of the method was tested in 1 cell block of malignant melanoma cells in pleural effusion, 10 ocular melanoma tissue samples, and 10 cutaneous melanoma tissue samples. Our results demonstrated that the proposed method, which can be performed in only 3 hours, effectively preserves cell cytomorphology and immunoreactivity. RESULTS: The method is particularly effective for removing melanin pigment to facilitate histopathological examination of cytomorphology and for obtaining an unmasked tissue section for immunohistochemical analysis.

Differential CD133 expression distinguishes malignant from benign papillary lesions of the breast.

Malignant papillary lesions are, in contrast to their benign counterpart, rare malignant tumors in the breast. To differentiate between benign or atypical and malignant papillary lesions can be difficult, especially in core biopsy specimens. In the present study, excisional or more extensive surgical specimens of 33 papillary carcinomas, 2 micropapillary carcinomas, and 17 atypical papillomas of the breast were reviewed and classified according to the latest WHO classification. Thirty-three intraductal papillomas and 49 invasive carcinomas, no special type (NST), were included in the study for comparison. CD133 expression in papillary carcinomas was significantly lower than that in benign and atypical papillomas (p < 0.001). CD133 expression in invasive carcinoma NST was also significantly higher than that in papillary carcinomas. Our data suggests that absence of expression of CD133 can be a useful marker in the differential diagnosis between malignant papillary lesions and their benign or atypical mimics. The characteristic loss of CD133 expression in papillary carcinomas of the breast also indicates that these lesions are distinct from other types of breast cancer.

Expression of OV-6 in primary colorectal cancer and rectal cancer with preoperative chemoradiotherapy: a clinicopathological study.

AIMS: OV-6 is among the best available markers of liver stem cells. The aim of this study was to investigate OV-6 expression and its clinical implications in colorectal cancer. METHODS AND RESULTS: Expression of OV-6 and its clinical implications were investigated in 94 patients with American Joint Committee on Cancer (AJCC) stage I-III primary colorectal cancer and in 37 rectal cancer patients who had received preoperative chemoradiotherapy. The two main expression patterns of OV-6 were cytoplasmic and membranous. Overexpression of OV-6, which was identified on the basis of overall staining intensity, was associated with perineural invasion, lymphovascular invasion, and early relapses. Membranous OV-6 overexpression was also significantly associated with depth of tumour invasion, AJCC stage, lymphovascular and perineural invasion, and postoperative early relapse. Disease-free survival and overall survival were significantly poorer in patients with high overall OV-6 expression than in those with low overall OV-6 expression (P = 0.015 and P = 0.029, respectively), and significantly poorer in patients with high membranous OV-6 expression than in those with low membranous OV-6 expression (P < 0.001 and P < 0.001, respectively). Membranous OV-6 expression was a more reliable prognostic marker than overall expression. CONCLUSIONS: OV-6 is not unique to the hepatobiliary system, and may be a novel prognostic marker in colorectal cancer.

Melanin bleaching with dilute hydrogen peroxide: a simple and rapid method.

Melanins are naturally occurring pigments in both normal and pathologic tissues. Two common bleaching processes are potassium permanganate followed by oxalic acid treatment and dilute hydrogen peroxide (H2O2) process. The potassium permanganate/oxalic acid method is faster and more easily incorporated in conventional daily immunostaining protocols, whereas the dilute H2O2 method requires 24 hours. This study aimed to reduce melanin bleaching time by using a 10% H2O2 dilution. First, reaction time was reduced to 30 minutes by raising the temperature to 65°C. Second, containers with high thermal conductivity were used to improve bleaching effectiveness. Experimental comparisons of melanin treatments with H2O2 contained in an iron jar, a glass coplin jar, and a plastic steel jar obtained bleaching time of 20, 30, and 40 minutes, respectively. These modifications of the conventional bleaching method significantly improve the speed and efficiency of the procedure and are recommended when performing immunohistochemical studies.

A high sensitivity three-dimensional-shape sensing patch prepared by lithography and inkjet printing.

A process combining conventional photolithography and a novel inkjet printing method for the manufacture of high sensitivity three-dimensional-shape (3DS) sensing patches was proposed and demonstrated. The supporting curvature ranges from 1.41 to 6.24 × 10(-2) mm(-1) and the sensing patch has a thickness of less than 130 µm and 20 × 20 mm(2) dimensions. A complete finite element method (FEM) model with simulation results was calculated and performed based on the buckling of columns and the deflection equation. The results show high compatibility of the drop-on-demand (DOD) inkjet printing with photolithography and the interferometer design also supports bi-directional detection of deformation. The 3DS sensing patch can be operated remotely without any power consumption. It provides a novel and alternative option compared with other optical curvature sensors.

Increased CD133 expression after preoperative chemoradiotherapy in rectal cancers other than mucin-rich tumors.

This study is to characterize the sequential change in CD133 expression after preoperative chemoradiotherapy (CRT) in rectal cancer and its impact on postoperative prognosis. Forty-one patients with rectal cancer who had received CRT before surgery were selected retrospectively. In each case, immunohistochemical analysis was performed to compare CD133 expression in biopsy specimens taken before and after CRT. After CRT, CD133 expression was significantly increased in 14 (34%) patients, mildly increased in 25 (61%), and decreased in 2 (5%). However, no mucin-rich tumors showed high CD133 expression before or after CRT (p < 0.001). Disease-free survival and overall survival were significantly poorer in patients with significantly increased CD133 (p = 0.049 and p = 0.038, respectively). Increased CD133 after CRT is a significant prognostic factor in rectal cancer patients treated with preoperative CRT and surgical resection. CD133 might be an essential cancer stem cell marker.