EGFR amplification and expression in oral squamous cell carcinoma in young adults.

The aim of this study was to investigate epidermal growth factor receptor (EGFR) gene alterations in two groups of patients with oral squamous cell carcinoma (OSCC) (a test group of subjects aged ≤40 years and a control group of subjects aged ≥50 years) and to associate the results with EGFR immunostaining, clinicopathological features, and the prognosis. Sixty cases of OSCC were selected (test group, n=21; control group, n=39). The tissue microarray technique was applied to ensure the uniformity of results. Gene amplification was analyzed by fluorescence in situ hybridization (FISH), and immunohistochemical staining for EGFR was analyzed using an automated imaging system. EGFR amplification was higher in the test group than in the control group (P=0.018) and was associated with advanced clinical stage (P=0.013), regardless of age. Patients with EGFR overexpression had worse survival rates, as did patients who had T3-T4 tumours and positive margins. EGFR overexpression has a negative impact on disease progression. Despite the higher amplification of EGFR in young adults, it does not significantly impact the survival rates of affected patients.

Hepatoblastoma and liver development: a study of cytokeratin immunoexpression in twenty-nine hepatoblastoma

Hepatoblastomas (HBs) recapitulate liver development. It is possible that HBs result from malignant transformation of hepatic precursor cells, and they may reflect a blockage in normal development. Here we study the expression of cytokeratins (CKs) in order to delineate the immunoprofile and relationship with liver development, as well as vimentin and alphafetoprotein (AFP), of HBs. Immunohistochemistry was performed in a tissue microarray (TMA) containing representative areas of 18 HBs (fetal and/or embryonal and/or mesenchymal); we also reviewed 11 cases not included in the TMA. No cases stained for CKs 1, 5/6, 7, 10, 13, 15, 16, 20, and 34betaE12. CK8 stained 73.07% of fetal, 50% of embryonal, and 18% of mesenchymal areas. CK18 stained 100% of epithelial areas. CK19 staining was intense and diffuse in 100% of embryonal samples, but it was weaker in fetal areas (66.66%). AE1 stained epithelial areas in all cases, and it stained 29.41% of mesenchymal areas. AE3 stained 84.61% of embryonal and 60% of fetal components. AE1/AE3 showed stronger staining in embryonal (100%) than in fetal areas (76.92%). Vimentin staining was strong in embryonal (66.66%) and mesenchymal (84.61%) components but weak in fetal areas (8%). Alphafetoprotein was positive in only 20% of fetal and 70% of embryonal areas. Our results support the hypothesis that immunoexpression of HBs follows the stages of normal liver development. Embryonal areas look less differentiated, expressing vimentin and biliary epithelium CKs, whereas fetal areas display a more developed phenotype, similar to that of mature hepatocytes. These data aid in understanding the ontogenesis of HBs and may be used in histopathological diagnosis

Antigen retrieval methods and estrogen receptor immunoexpression using 1D5 antibody: a comparative study.

Long-term formalin tissue fixation results in antigen masking, probably through aldehydic linkage between proteins and fixative molecules. Immunohistochemistry results depend on the type of the detection procedure and the type of antibody used for the reaction. Considering the difficulty in working with estrogen receptor (ER) antibodies and the lack of standardization of the antigen retrieval methods, we quantified the immunoexpression of ER using the 1D5 antibody and a standard streptavidin-biotin detection procedure retrieving with microwave oven, steamer, pressure cooker, and water bath in a set of SBR grade 2 invasive breast carcinomas. Pressure-cooking provided the best results. No significant differences were observed in using the other methods. Pressure-cooking should be recommended as the method of choice for standardization of the ER immunohistochemical reaction.

Immunocytochemical study of malignant lymphoma in serous effusions.

OBJECTIVE: To cytologically evaluate a large series of serous effusions associated with malignant lymphoma (ML), identify the immunoreaction patterns of the cells from selected positive cases and to investigate the correlation of cytomorphology with tissue section diagnosis. STUDY DESIGN: From 1966 to 1990, a review of the files of the Department of Anatomic Pathology, A. C. Camargo Hospital, disclosed 4,297 cases of serous effusions, 256 of which were associated with ML. Cytopathologically positive cases were selected for immunocytochemical study. All paraffin sections stained with hematoxylin and eosin were reviewed to confirm the malignancy of the cases. Immunostaining was performed on both cytocentrifuge slides previously stained with Papanicolaou stain and new sections of the biopsy samples using the immunoperoxidase method and avidin-biotin complex with monoclonal mouse antihuman B-cell marker L-26 and monoclonal (mouse) antihuman T-cell marker UCHL-1. RESULTS: Immunocytochemical reactions were performed in 54 cases: 22 were pan-B positive and 10 pan-T positive; 24 cases showed no reactivity for either monoclonal antibody. Immunohistochemical reactions were performed in 24 available cases: 15 were pan-B positive and pan-T positive; 3 cases showed no reactivity for either monoclonal antibody. Cytohistoimmunoreactions were similar in 11 pan-B positive cases and 2 pan-T positive cases. Three cases were negative for both markers, 4 cases were pan-T positive in tissue samples and negative in cytocentrifuge smears, 3 cases were pan-B positive in tissue and negative on cytology and 3 cases were negative for both markers in both tissue and cytologic specimens. CONCLUSION: Cytology is an effective method of evaluating serous effusions associated with malignant lymphoma: no false positive diagnosis was observed in this series. Immunophenotyping of lymphoid cells is useful to classify and confirm the cytologic diagnosis.

Cytologic diagnosis of melanoma in serous effusions. A morphologic and immunocytochemical study.

The diversity of melanoma patterns greatly impairs the interpretation of malignant cells in effusion samples. The presence of melanin pigments greatly helps determine the histogenetic origin of the tumor, but unfortunately many cases do not exhibit this feature. We reviewed cases with a definitive diagnosis of melanoma in order to identify some useful characteristics of the morphologic examination of effusions. We also subjected the effusions to the HMB45 immunoreaction to determine the diagnostic usefulness of this monoclonal antibody. The study was performed on 21 effusion samples containing malignant cells, and the main cytologic findings were similar to those on other neoplasms except for the presence of melanin pigment. The HMB45 immunoreaction was very sensitive, confirming the diagnosis in 14 of 18 cases (77.8%). Melanin pigments seem to be useful markers for melanoma in effusions, and HMB45 can be used as an ancillary method in the differential diagnosis.