[Immunocytochemical identification of carcinomas of unknown primaries on fine-needle-aspiration-biopsies]. / Immunzytochemische Abklärung des initialen CUP-Syndroms an Feinnadelpunktaten.

Clinical investigations with imaging- and endoscopic techniques in order to identify the primary tumor sites in patients with CUP syndrome generally entail a significant diagnostic effort. If costs exceed 800.00, a financial loss ensues for German hospitals, as public health insurance companies do not reimburse above this amount. Combined cytological/immunocytochemical investigation of metastatic cancer cells represents a cost-effective, minimally invasive procedure to identify the probable primary cancer site that can be applied on an outpatient basis. We report on 85 fine needle aspiration biopsies of metastases to the liver, 30 to the lymph nodes and over 180 serous effusions and/or ascites with metastatic cancer cells in CUP. After conventional microscopic inspection, a routine panel of six monoclonal antibodies was applied (CK 5/6, CK 7, CK 20, Cdx 2, TTF 1 and CA 125). We were thus able to correctly identify the primary tumor sites in 90.3%, 92.0% and 85.1%, respectively, within three days. In total, 23 primary hepatocellular carcinomas could all be classified correctly, applying the antibodies HepPar 1, BerEp 4, AFP, CD 31, CD 68 and Ki 67. In addition, 141 malignant epithelial mesotheliomas were typed correctly in 97.1%, using the antibodies BerEp 4, Calretinin, Mesothelin, EMA and WT. Therefore, immunocytochemical investigation of metastatic cancer cells from fine needle aspiration biopsies or in serous effusions offers an efficient, cost-effective diagnostic alternative to imaging and endoscopic techniques in the workup of patients with CUP syndrome.

Early diagnosis of mesothelioma in serous effusions using AgNOR analysis.

OBJECTIVE: To compare the results of conventional cytology, DNA image cytometry, immunocytochemistry and argyrophilic nucleolar organizer region (AgNOR) analysis for the diagnosis of malignant cells in serous effusions. STUDY DESIGN: One hundred twenty effusions, 40 with carcinoses, 40 with malignant mesotheliomas and 40 without tumor cells on follow-up were studied by conventional cytology and three adjunctive methods. RESULTS: Unequivocal tumor cells were detected in 92.5% of effusions due to carcinoses and in 45% due to mesotheliomas. Applying immunocytochemistry with BerEP-4 positivity and DNA image cytometry with aneuploidy as a marker revealed 100% of carcinoses and 71.7% of mesotheliomas. Applying the experimentally found thresholds of 2.5 AgNORs as "satellites" and 4.5 AgNORs as "satellites and clusters" together as mean values per nucleus resulted in a 95% correct rate of mesothelioma and 100% rate of carcinoma cell identification without false positive diagnoses. CONCLUSION: AgNOR analysis may be a useful adjunct to other methods in the routine diagnosis of malignant serous effusions. It seems to be the most sensitive method in early cytologic diagnosis of mesotheliomas in effusions. Seventy-three percent of malignant mesotheliomas were diagnosed cytologically at first on effusions. Forty-seven percent of patients with malignant mesotheliomas were identified at the early tumor stage T1 N0 M0.