Manfred Droese

Cytologic diagnosis of medullary carcinoma of the thyroid gland.

The cytomorphologic features in fine‐needle aspiration (FNA) biopsies from 91 histologiacally verified medullary carcinomas of the thyroid (MCT) were investigated. FNA was able to diagnose neoplasms with indications of surgical removal in 98.9% of cases and moreover, was accurate in specific tumor typing in 89% of cases. The most important cytologic criteria of MCT with FNA are: dispersed cell‐pattern of polygonal or triangular cells, azurophilic cytoplasmic granules, and extremely eccentrically placed nuclei with coarse granular chromatin and amyloid. These and other cytologic features of MCT are discussed in detail. Fourteen cases of thyroid tumors originally diagnosed as MCT by cytology are illustrated to discuss the differential diagnosis of MCT and its potential pitfalls. If MCT is cytologically presumed but amyloid and azurophilic cytoplasmic granules are not demonstrated, the use of immunostaining is necessary for a correct tumor typing. The application of immunocytochemistry in MCT is discussed. Diagn. Cytopathol. 22:351–358, 2000.

Keratin polypeptide distribution in benign and malignant breast tumors: subdivision of ductal carcinomas using monoclonal antibodies.

SummaryMonoclonal antibodies which recognize one or only a few keratin polypeptides have been used to study the distribution of different keratins in benign and malignant breast lesions by immunocytochemical methods. Seven monoclonal antibodies which recognized either different keratin polypeptides by immunoblotting techniques, or identified different epithelial cell types in complex tissues were used. In two mastopathies and three fibroadenomas the antibody 1u5 stained luminal cells as well as myoepithelial cells. In contrast the antibodies CK7, Troma 1, CK2 and KA4 labeled only luminal cells, whereas antibody CKB1 decorated only myoepithelial cells. All 15 ductal carcinomas showed a uniform staining of tumor cells with the antibodies Troma 1, CK2, KA4 and 1u5. The antibody CK7 also stained all ductal carcinomas, but in two specimens the staining was heterogeneous. The antibody CKB1 decorated only the preexisting myoepithelial cells in 11 of 12 ductal carcinomas but in the remaining specimen the tumor cells were also strongly positive. Tumor cells in lobular carcinomas were labeled by antibodies CK7, Troma 1, CK2, KA4, but not by CKB1. The antibody CKS1 showed no staining of any of the benign and malignant breast lesions.

POINT MUTATIONS AND NUCLEOTIDE INSERTIONS IN THE MDM2 ZINC FINGER STRUCTURE OF HUMAN TUMOURS

This study investigates the human oncoprotein MDM2, which interferes with regulation of cell division and apoptosis. Fifteen mixed–type follicular non‐Hodgkins lymphomas, ten leukaemias, two hepatocellular carcinomas, one osteosarcoma, and ten normal cell lines (fibroblasts, osteoblasts, mesothelium, peripheral lymphocytes) were tested for MDM2 expression and MDM2 gene mutation by reverse transcriptase‐polymerase chain reaction (RT‐PCR), immunocytochemistry, and nucleotide sequence analysis. Two follicular lymphomas, three leukaemias, both hepatocellular carcinomas, and the osteosarcoma sample showed transcription of the activated MDM2 gene. These samples lacked amplified MDM2 genes and carried mis‐sense, non‐sense and frame‐shift mutations in a zinc finger region of MDM2, altering the amino acid sequence or causing premature termination of transcription. The mis‐sense mutations were found in tumour cells that showed significant accumulation of MDM2 and lack of nuclear p53. Non‐sense mutations and frame‐shift mutations were found in tumours lacking MDM2 proteins. The mutations may affect the biological properties of MDM2 proteins.

Cytologic diagnosis of adenoid cystic carcinoma of salivary glands

The cytomorphologic features in fine‐needle aspiration (FNA) biopsies from 31 primary and 33 recurrent adenoid cystic carcinomas (ACC) were investigated. The correct FNA diagnosis was established in 24 of 31 primary ACC (77%). The diagnostic clue in aspirates from ACC are large globules of extracellular matrix, partially surrounded by basaloid tumor cells. In FNAs with predominance of basaloid tumor cells, but lacking characteristic globules, all other benign and malignant salivary gland tumors of epithelial‐myoepithelial differentiation should be considered in the cytologic diagnosis. Pleomorphic adenoma is most frequently confused with ACC, and therefore, the cytologic findings in FNAs from 50 pleomorphic adenomas were compared with those diagnosed as ACC. Furthermore, rare neoplasms of salivary glands with epithelial‐myoepithelial cell differentiation, including basal‐cell adenoma and carcinoma, epithelial‐myoepithelial carcinoma, and polymorphous low‐grade adenocarcinoma, as well as some nonsalivary gland neoplasms presenting an adenoid cystic pattern, must be considered. The cytologic features of these entities are discussed in detail with respect to the cytologic diagnostic criteria of ACC. Diagn. Cytopathol. 1999;20:358–366.

Cytologic diagnosis of acinic-cell carcinoma of salivary glands.

The cytologic findings in fine‐needle aspiration (FNA) biopsies obtained from 40 primary and 18 recurrent acinic‐cell carcinomas (ACC) were retrospectively analyzed. Cytomorphologically, ACC is characterized by acinar differentiated tumor cells. In addition to these diagnostic clue cells, other types of neoplastic cells including vacuolated cells, cells resembling oncocytes, and nonspecific glandular cells are encountered. A pronounced lymphocytic reaction is a hallmark in 10% of ACC aspirates. Both the variety of tumor cell differentiation and the pronounced lymphocytic reaction observed in ACC aspirates may result in confusion with other salivary gland lesions. The differential diagnosis of ACC encompasses adenocarcinoma, mucoepidermoid carcinoma, pleomorphic adenoma, Warthin tumor, sebaceous lymphadenoma, benign lymphoepithelial lesion, sialoadenosis, sialadenitis caused by radiotherapy, and lymphadenitis. Primary ACCs were correctly diagnosed in 68%; additionally, ACC was suspected or included in the differential diagnosis in 15%. Increased familiarity with the spectrum of cytomorphologic findings and the potential diagnostic pitfalls in ACC will improve the cytodiagnosis of this neoplasm. Diagn. Cytopathol. 16:402–412, 1997.

Histochemical and immunohistochemical detection of putative preneoplastic liver foci in women after long-term use of oral contraceptives.

SummaryLocalized areas with altered enzyme patterns were observed in liver tissue surrounding focal nodular hyperplasia in women after long-term use of oral contraceptives. These localized lesions were of three different types. Type I lesions were characterized by glycogen storage, a reduction in ATPase and an increase inγ-glutamyltranspeptidase (γ-GT) and UDP-glucuronyltransferase (UDP-GT) detected immunohistochemically. Type II lesions, which were morphologically very similar to small hyperplastic nodules, showed only a decreased ATPase reaction. Type III lesions showed an increase inγ-GT (detected histochemically) and a slight reduction in ATPase. The results indicated that in human liver from patients given oral contraceptives long-term, localized lesions with altered enzyme patterns may occur which are very similar to those observed in animal models during experimental hepatic carcinogenesis.

The Value of Anti-Calretinin Antibody in the Differential Diagnosis of Normal and Reactive Mesothelia versus Metastatic Tumors in Effusion Cytology

In effusion cytology the distinction of reactive mesothelia from metastatic carcinoma cells may be a diagnostic challenge. Immunocytochemistry using antibodies suitable to detect epithelial cells must be considered carefully due to limited sensitivity and specificity of these antibodies. Efficient results in histological differential diagnosis of malignant mesothelioma versus lung-adenocarcinoma applying a novel antiserum against the calcium binding protein calretinin inspirated us to investigate the value of anti-calretinin antibody in effusion cytology combined with an epithelial marker. Cytoslides prepared by cytocentrifugation from 42 malignant and 65 reactive effusion specimens were immunostained using antibodies against calretinin and the epithelial marker Ber-EP4. Positive immunoreaction for calretinin in normal and reactive mesothelial cells was noted in 93% of the cases, whereas immunoreaction for calretinin was completely negative in the metastatic cells in 95% of the malignant effusions. Metastatic carcinoma cells were detected with anti-Ber-EP4 in 83% of malignant effusions. Non-specific positive reactions for Ber-EP4 in single mesothelial cells were observed in 16% of all cases and, moreover, frequently with macrophages or neutrophilic granulocytes. Our results demonstrate high sensitivity and specificity of anti-calretinin antibody for mesothelial cells in effusion specimens. They support its application to improve the diagnostic reliability of epithelial markers, especially because anti-calretinin antibody could be helpful in the assessment of false positive and false negative reactions of epithelial markers.

Diagnostic value of intermediate filament antibodies in clinical cytology

SummaryAntibodies to intermediate filament (IF) proteins can distinguish the major tumor groups as shown by results with sectioned human material. In this study we evaluate the use of similar methods in the cytology of human tumors. Smears obtained from fine needle aspiration biopsies were investigated using well characterized antibodies, each specific for only one of the five types of intermediate filaments. Tumor cells of different carcinomas, thymomas, and the epithelial part of pulmonary blastomas were positive with antibodies recognizing cytokeratins. Tumor cells in non-muscle sarcomas, including lymphoma and Ewings sarcoma, could be specifically identified with antibodies to vimentin. Tumor cells of muscle sarcomas were desmin-positive. Finally, tumor cells in pheochromocytoma and bronchus carcinoid were positive with antibodies specific for neurofilaments. Specimens were also examined in parallel using conventional cytochemical stains, such as May-Grünwald-Giemsa. In addition, in most cases sections of the tumor were examined both by histology and IF typing of frozen sections to confirm the diagnosis made on the cytologic specimens. The results show that IF typing is a valuable diagnostic aid in clinical cytology.

Tumor-associated antigens in effusions of malignant and benign origin

SummaryWe determined the concentration and effusion/serum ratio of mucin-like carcinoma-associated antigen (MCA) in comparison to carcinoembryonic antigen, carbohydrate antigen 19-9, cancer antigen 125, and cancer antigen 15-3 in 80 sera and 99 effusions from 64 patients with histologically confirmed malignancies (4 patients out of this group showed various effusions simultaneously, which were analyzed separately) and 31 patients with various nonneoplastic diseases. Tumor cells were detected by cytological examination in 41 effusions (60.3%) from patients with neoplastic diseases, while in another 27 cases this method failed to demonstrate the malignant origin of the effusion. Of the cytological “positive” malignant effusions 90% were also correctly identified by an elevated MCA concentration at a cutoff level of 10 U/ml, whereas only one effusion of benign origin (3%) showed a slightly elevated MCA concentration of 10.5 U/ml. In 33% of cytologically “negative” effusions of patients with neoplastic diseases, the MCA concentration was also elevated, with a maximum of 453 U/ml. Increased MCA levels in cytologically confirmed malignant effusions were not restricted to metastatic breast cancer. All 17 cytologically “positive” “non-breast cancer” effusions were correctly identified by their MCA concentrations. None of the other tumor markers reached this high sensitivity at the same level of specificity. The ratio of effusion/serum concentration of all tumor markers as well as the concentration of cancer antigen 125 in effusions was of little diagnostic value. Our results indicate that the MCA concentration in an effusion correlates very closely with its malignant origin and is superior to all the other antigens tested. Accordingly, the concurrent MCA determination could improve the diagnostic accuracy of the cytological examination of effusions.

The In Situ Polymerase Chain Reaction for Detection of Chlamydia trachomatis

The in situ polymerase chain reaction (PCR) is a technique that has important applications in the diagnosis of viral and bacterial diseases. This study investigated an in situ PCR assay established to detect the presence of Chlamydia trachomatis in endocervical swabs. In addition, histological sections of endocervical squamous cell carcinoma were analyzed because previous studies had revealed a significant association with C. trachomatis. A total of 20 cervical neoplasms (squamous cell carcinoma in situ; n = 10; invasive squamous cell carcinoma; n = 10) and endocervical smears taken from five patients with and without inflammatory changes were analyzed by conventional PCR. Chlamydial DNA was found in 10 histological samples (six carcinomas in situ, four invasive carcinomas) and in one endocervical swab from a patient with known C. trachomatis infection. Positive specimens were used for establishing an in situ PCR assay (IS-PCR). After IS-PCR, these samples showed dense cytoplasmic staining of endocervical cells (smears) and non-neoplastic epithelial cells (cervical neoplasms). The other tumor samples and smears did not demonstrate positive PCR reaction. The results indicate that in situ PCR is an effective technique for localizing C. trachomatis in target cells because IS-PCR detection of chlamydial DNA correlated with histological and cytological features.