Morphologic studies of gastric stromal tumors (GSTs) indicate that mitotic counts (MCs) and tumor size are major discriminants predictive of biologic behavior. The authors evaluated the tumor proliferation of GSTs with anti-proliferating cell nuclear antigen (PCNA; DAKO clone PC10, DAKO Corporation, Carpinteria, CA) for correlation with MCs, histologic cell type, and clinical outcome. Fifty-eight tumors ranging from 1.5 to 45 cm in size were selected for clinicopathologic assessment. Mitotic activity was counted per 50 high-power fields (MC). For this study, combined parameters of MC and tumor size were used to categorize tumors into three groups: (1) benign: MC less than 5, tumor smaller than 5 cm; (2) borderline: MC less than 5, tumor larger than 5 cm; and (3) malignant: MC greater than 5, tumor any size. The PCNA tumor proliferation index (TPI) was assessed from evaluation of 200 tumor cells per case and expressed as the percentage of cells with positive results. Clinical follow-up was available in 45 cases. None of the 19 benign or 16 borderline tumors recurred or metastasized, whereas 7 of 10 malignant tumors metastasized and 1 of 10 recurred. The mean PCNA TPI values among benign (11.2%), borderline (16%), and malignant (34.5%) tumors were significantly different (P = 0.0002, Kruskal-Wallis test). When the pathologic tumor categories were compared, the mean TPI of benign tumors was significantly different from that of borderline tumors (P = 0.0306, Kruskal-Wallis), and the TPI of borderline tumors was different from that of the malignant tumors (P = 0.0060, Kruskal-Wallis test). The Spearman rank correlation showed a significant relationship between the MC and PCNA TPI (P = 0.0003, r = 0.4543). Logistic regression analysis showed that the TPI, independent of MC and size, contributed significantly (P = 0.00295) to the prediction of outcome. In the malignant group, the mean TPI for malignant tumors with metastases (43.6%) was significantly different (P = 0.0411, Kruskal-Wallis test) from that of malignant tumors without metastases (including the case with probable recurrence) (11.83%). No correlation was found when PCNA TPIs for epithelioid GCTs were compared with those of spindle cell GSTs.(ABSTRACT TRUNCATED AT 400 WORDS)

The authors present an improved method for rapid two-color staining with direct conjugated antibodies to cytokeratin and CD45 antigen (leukocyte common antigen) for whole-cell, ethanol-fixed preparations of human carcinomas. This method was quality controlled with the T24 human bladder tumor cell line and compared in parallel analysis of 24 fresh human carcinomas with the original two-color method of multiparametric analysis that had been published in 1989. This rapid method was designed to achieve comparable staining intensities of both green (phenotype directed monoclonal antibody label) and red (propidium iodide labeled DNA) fluorescence, identical DNA indexes, comparable coefficients of variation, and subjective visual quality of DNA histograms. This is accomplished in a single (one-shot), abbreviated incubation with monoclonal antibody diluted in propidium iodide-RNase, thereby eliminating two incubations and three wash steps required with the original method. The single rinse is done in the propidium iodide-RNase staining solution with resuspension in fresh staining solution before analysis. With the rapid method, the preparation time is reduced by 130 minutes, resulting in a 60% time savings in batch staining mode compared with the original method. The time reduction and fewer wash steps, which should avoid excessive cell loss and cytoplasmic stripping, may advance the adoption of this two-color method in clinical practice.

The risk of HER2/neu positive breast carcinoma differs between African-American and White women. For White women only, this risk was statistically significant and increased almost linearly within each TNM stage with grade dedifferentiation. The statistically significantly higher prevalence of "ER(-)/PR(-), HER2(- )" phenotype in African American women potentially is the attributing factor to observed lack of an association between the risk of HER2/neu positive breast carcinoma with advanced stages and poorly differentiated grade. Among women diagnosed with "ER(-)/PR(-), HER2(-)" phenotype the odds ratios of being African-American and pre-menopausal was 1.72 (95% CI 1.17-2.54, P = 0.006) and 1.94 (95% CI 1.27-2.96, P = 0.002), respectively. The histologic features of basal-like and ER(-)/HER2(+ )carcinomas overlaps. Differences in the biology of breast carcinoma between African American and White women are partially attributed to the disparity in more adverse pathologic prognostic indicators at the initial clinical presentation of this disease.

Our objective was to assess the loss of E-cadherin (EC) as a diagnostic marker or a predictor of prognosis. We stained 276 breast carcinomas with monoclonal antibodies to EC (invasive lobular carcinomas [ILC] and variants, 59; invasive ductal carcinoma and ductal special types [IDC], 204; tubulolobular carcinoma [TLC], 4; and invasive carcinoma [IC], uncertain whether lobular or ductal type, 9). The results were as follows: EC+IDCs, 99.5%; EC-ILCs, 90%; EC+ILCs, 10%; EC+pleomorphic ILCs, 20%; EC-ICs, 44%. All 4 TLCs showed positive tubules while cords were negative. Statistically a correlation of EC loss with a positive diagnosis of ILC was found but there was no correlation with any prognostic tumor variables. A negative EC stain confirms the diagnosis of ILC (specificity, 97.7%; negative predictive value, 96.8%; sensitivity, 88.1%; positive predictive value, 91.2%). EC is helpful in classifying cases with indeterminate histologic features. EC loss is uncommon in nonlobular carcinomas with no correlation to currently established prognostic variables.

SF is a fibrotic lesion with cells positive for CD34 and O13. It shares a common immunoprofile with PF but is distinct from dermatofibroma and other common spindle cell lesions of skin. O13 expression in SF has not been previously described.