Myoepithelial carcinoma of the salivary glands: a clinicopathologic study of 25 patients.

Salivary gland carcinomas displaying exclusively myoepithelial differentiation (myoepithelial carcinoma) are considered rare. Their histopathologic features, immunohistochemical profile, and clinical behavior are not well characterized. The authors reviewed the clinicopathologic features of 25 salivary gland tumors fulfilling two fundamental histologic criteria: unequivocally malignant and exclusively myoepithelial. For most of these, the original diagnosis was malignant mixed tumor. Thirteen men and 12 women aged 24 to 77 years (mean age, 55 yrs) participated in the study, and most presented with a painless mass. The parotid gland was the most common site (n = 15). Tumors ranged from 2.1 to 5.5 cm, arising either in association with a benign mixed tumor (n = 15) or de novo (n = 10). Histologically, all the tumors displayed infiltrative growth and most had a characteristic multinodular architecture with a cellular periphery and central necrotic/myxoid zones. Epithelioid, hyaline, spindle, clear, or mixed cell types were noted with accompanying myxoid and/or hyalinized extracellular matrix. Ten tumors were high grade cytologically and 15 were low grade. The mitotic rate ranged from three to 51 mitoses per 10 high-power fields. Necrosis was present in 15 tumors and perineural and vascular invasion were identified in 11 and four neoplasms respectively. Immunoreactivities included CAM5.2 (89%), AE1:AE3 (100%), 34betaE12 (92%), cytokeratin 7 (21%), cytokeratin 14 (53%), vimentin (100%), S-100 protein (100%), smooth muscle actin (50%), calponin (75%), muscle-specific actin (31%), glial fibrillary acidic protein (31%), carcinoembryonic antigen (0%), and epithelial membrane antigen (21%). Ultrastructural examination of three tumors showed myoepithelial features. Ten patients developed recurrences, mostly multiple. Follow up of 17 patients showed that eight patients (47%) developed metastases (six high grade, two low grade) and five patients (29%) died of disease (four high grade, one low grade) after a mean of 32 months. Two patients were alive with disease (19 and 49 mos). Ten patients (59%) were without any evidence of disease after a mean of 42.2 months. Myoepithelial carcinomas exhibit a wide spectrum of cytomorphologic features and diverse clinical outcomes. As a result of their morphologic heterogeneity, they can be confused easily with many tumors. Myoepithelial carcinomas have been underrecognized in the past, primarily by being lumped under a broader category of "malignant mixed tumor." Awareness of their unique cytoarchitectural patterns and immunohistochemical profile is crucial for accurate identification.

Immunohistochemical markers of prolonged survival in small cell carcinoma of the lung. An immunohistochemical study.

OBJECTIVE: To investigate the association of a variety of cell surface and cytoplasmic antigens in small cell carcinoma of the lung with long-term survival (greater than 2 years). DESIGN: Using immunohistochemical analysis of small cell carcinomas, the tissue expression of corticotropin, bcl-2, p-glycoprotein, cathepsin B, cathepsin D, CD44, carcinoembryonic antigen, collagenase IV, Leu-7, neu oncoprotein, p53, S100, and synaptophysin was assessed. RESULTS: Compared with the control group of short-term survivors, tumors from prolonged survivors were unique in their relative absence of staining for cathepsin B (0/13 vs 3/13 [23%], P = .037), cathepsin D (5/13 [38%] vs 13/15 [87%], P = 0.006), carcinoembryonic antigen (5/13 [38%] vs 11/15 [73%], P = .047), and neu oncoprotein (5/13 [38%] vs 14/15 [93%], P = .0014). A variety of histologic characteristics were also compared, and none were shown to be associated with differences in survival in this study. CONCLUSIONS: Negative immunohistochemical staining for cathepsin B, cathepsin D, carcinoembryonic antigen, and neu oncoprotein is associated with prolonged survival in small cell carcinoma of the lung. Evaluation of these antigens should be considered in future attempts to stratify patients with small cell carcinoma of the lung for prognostic or therapeutic purposes, as this study is limited by the small size of the study group and the large number of clinical and pathologic variables.

Transferrin allelic variants may cause false positives in the detection of cerebrospinal fluid fistulae.

Variations in either the polypeptide sequence or the carbohydrate moieties of transferrin may result in altered electrophoretic mobility of this molecule. We report a case of an allelic (polypeptide) variant of transferrin with mobility similar to that of the beta 2 (sialic acid-depleted) transferrin found in cerebrospinal fluid (CSF) and a few other body fluids. Allelic variation and other transferrin anomalies may be mistaken for the CSF isoform, resulting in false diagnoses of CSF fistulae.

Predicting death in patients hospitalized for community-acquired pneumonia.

OBJECTIVE: To validate a previously reported discriminant rule for predicting mortality in adult patients with primary community-acquired pneumonia and to determine which factors available at hospital admission predict a fatal outcome among such patients. DESIGN: Historical cohort study. SETTING: University hospital. PATIENTS: Adults admitted to the hospital for community-acquired pneumonia. MEASUREMENTS: Using stepwise logistic regression, we analyzed prognostic factors (data available at admission and recorded in the medical record) that showed a univariate association with mortality. The predictive values of three discriminant rules were measured to validate the results of a previous study. MAIN RESULTS: Of 245 patients, 20 (8.2%) died. Of 42 prognostic factors identified in previous studies, 8 were associated with mortality, but only a respiratory rate of 30/min or more, a diastolic blood pressure of 60 mm Hg or less, and a blood urea nitrogen of more than 7 mmol/L remained predictive in the multivariate analysis. A discriminant rule composed of these three variables was 70% sensitive and 84% specific in predicting mortality, yielding an overall accuracy of 82%. CONCLUSION: Tachypnea, diastolic hypotension, and an elevated blood urea nitrogen were independently associated with death from pneumonia in our study, confirming the value of a previously reported discriminant rule from the British Thoracic Society. This rule may be useful in triage decisions because it identifies high-risk patients who may benefit from special medical attention.

The interaction of antibody/DNA immune complexes with complement. Influence of antibody class and DNA conformation.

In 28 serum and plasma samples from patients with systemic lupus erythematosus, we examined the importance of antibody class with respect to complement-mediated binding to human red blood cells (RBC) of antibody/DNA immune complexes (IC) prepared with anti-DNA antibodies. We used both 3H-double-stranded DNA and 3H-single-stranded DNA (ssDNA). Generally, double-stranded DNA IC showed considerably higher binding than did ssDNA IC in the RBC binding assay. Further analysis indicated that although ssDNA IC fix complement, it is necessary that these IC contain IgM anti-DNA antibodies in order for them to bind to RBC. The results suggest that the mechanisms of clearance and pathogenic potential of these IC may depend upon both the DNA conformation and antibody class. In particular, complement-fixing IC which contain IgG anti-DNA antibodies and ssDNA may not be cleared via the erythrocyte clearance mechanism, and therefore, could be more likely to deposit in certain tissues and initiate inflammatory reactions.