Immunocytochemistry and DNA-image cytometry in diagnostic effusion cytology I. Prevalence of markers in tumour cell positive and negative smears.

To determine the prevalence of immunocytochemical positivities for a panel of antibodies in benign and malignant cells in effusions with known follow-up in order to use these as diagnostic markers. Besides their ability to identify malignant epithelial cells their contribution to the differential diagnosis between carcinomatoses and mesotheliomas was investigated. 101 tumour cell positive and 53 negative effusions were stained with 12 different antibodies. Results were scored semiquantitatively per cell type. Furthermore, DNA-image cytometry was performed. While prevalence of Ber-EP4 positivity was 95.4% in metastatic carcinoma cells, it was 0% in those from mesotheliomas. No cell type reacted with this marker in benign effusions (0%). Ber-EP4 correctly differentiated between metastatic carcinoma and mesothelioma in 98.0%. Prevalence of DNA-aneuploidy was 95.4% in metastatic carcinomas, 57.1% in mesotheliomas and 0% in reactive effusions. Combining immunocytochemistry (Ber-EP4 positivity) and DNA-image cytometry (aneuploidy) results in a 100% detection of metastatic carcinomatoses and 57.1% of mesotheliomas. Both markers furthermore allowed a correct differentiation of these entities in 98%.

Immunocytochemistry and DNA-image cytometry in diagnostic effusion cytology. II. Diagnostic accuracy in equivocal smears.

To determine sensitivity and specificity of different antibodies for the immunocytochemical detection of malignant cells in diagnostically equivocal effusions in comparison with those achieved by DNA-image cytometry. 65 cytologically doubtful effusions of the serous cavities were stained with twelve antibodies. Furthermore, DNA-image cytometry was performed. Data were correlated with patient follow-up. Sensitivity of cellular staining of Ber-EP4 for the identification of malignant cells was 77.8%, specificity of absent staining for benign cells was 100%. Positive predictive value for the identification of malignant cells was 100%, negative value 65.5%. Sensitivity of DNA-aneuploidy for the identification of malignancy was 82.9%, specificity of DNA-non-aneuploidy for benignity 94.7%. The positive predictive value of DNA-aneuploidy for the occurrence of malignant cells was 96.7%. Negative predictive value of DNA-non-aneuploidy was 72.0%. Combining immunocytochemistry applying Ber-EP4 only and DNA-cytometry in equivocal effusions resulted in a sensitivity of 88.9% for the identification of malignant cells associated with a 95.0% specificity. Positive predictive value was 97.7%, the negative one 79.2%.

MIB-1 (Ki-67) immunostaining of breast cancer cells in cytologic smears.

OBJECTIVE: The reliability of immunocytochemical evaluation of proliferation activity was tested using the monoclonal antibody MIB-1 on cytologic specimens. STUDY DESIGN: The study comprised 83 frozen tissue smears (FTSs) and 51 fine needle aspirates (FNAs) from 119 breast cancer patients. MIB-1 labeling indexes (LIs) were compared with various tumor parameters assessed on histologic material. RESULTS: MIB-1 LIs established on cytologic smears were significantly different in ductal and lobular carcinomas (P = .024) and correlated significantly with mitotic activity (P < .0001), histologic grade (P < .0001) and S-phase fraction (P < .0001). Essentially the same results were obtained on FTSs and FNAs. CONCLUSION: Proliferative activity can reliably be evaluated by FNA cytology, and the evaluation of MIB-1 LIs may complement cytologic grading of breast cancer. The evaluation of proliferation activity may, therefore, contribute to the selection of candidates for adjuvant chemotherapy.