Significance of intercellular spaces (windows) in effusion fluid cytology: a study of 46 samples.
ABSTRACT The presence and nature of intercellular windows were studied on 46 body cavity fluid samples chosen on the basis of an unequivocal diagnosis on May-Grünwald-Giemsa (MGG)/Papanicolaou-stained smears and cell blocks. Of these, 24 cases had adenocarcinoma (AC) and seven had reactive mesothelium (RM) with 15 having distinct populations of both. Mucicarmine and PAS stains were used wherever indicated. The specificity of windows for predicting reactive mesothelium was evaluated. Intercellular windows were found in all cases of reactive mesothelium coinciding with the presence of the fuzzy peripheral microvillous borders. Surprisingly, as many as 17/39 (44%) of the adenocarcinomas also exhibited this feature, of which 13 had a distinctly visible evenly distributed ciliated cell membrane. In addition, 30/39 (77%) cases of AC exhibited a "window-like" appearance caused by cytoplasmic vacuolation. None of the adenocarcinoma clusters with true window formation showed positivity for the mucin stains, whereas all the clusters with pseudowindows caused by vacuolation were stained. Thus the specificity of intercellular windows for RM was merely 56%, though the sensitivity was 100%. On the other hand, the absence of windows was 100% specific for adenocarcinoma. Intercellular windows, though a feature of reactive mesothelial cell populations, can also be found in cases of ciliated adenocarcinomas and may not have a significant predictive value.
- Diagnostic Cytopathology 09/1998; 19(2):131-7. · 1.49 Impact Factor
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ABSTRACT: The application of cytomorphologic criteria to the examination of serous effusions allows the reliable diagnosis of malignancy in the majority of cases. One feature observed in tissue fragments previously thought to be indicative of mesothelial origin is the presence of intercellular windows, presumably due to long surface microvilli. In this study, however, we examined cytologic preparations of 143 effusion and body-cavity washing specimens and noted distinct intercellular window formation within tissue fragments of adenocarcinoma in 13% of the cases studied. Stains for mucicarmine, Alcian blue with hyaluronidase pretreatment, and periodic acid-Schiff following diastase digestion on corresponding cell block material demonstrated that intercellular mucin contributes to such window formation in greater than half of these cases. Thus the presence of intercellular windows within tissue fragments does not, in isolation, preclude the diagnosis of malignancy in serous effusions.Diagnostic Cytopathology 04/1999; 20(3):115-9. · 1.49 Impact Factor
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ABSTRACT: The objective of the present study was to analyze the role of the mesothelial markers desmin and N-cadherin in the diagnostic panel of serous effusions. A total of 181 pleural and peritoneal effusions consisted of 101 cases cytologically diagnosed as malignant (89 carcinomas, 12 mesotheliomas), 78 benign, and 2 inconclusive specimens. All specimens were immunostained using 11 antibodies, against epithelial membrane antigen, Ber-EP4, carcinoembryonic antigen, E-cadherin, CA 125, N-cadherin, desmin, calretinin, p53, vimentin, and CD45. After evaluation of immunocytochemistry results, 110 specimens were diagnosed as malignant (98 carcinomas, 12 mesotheliomas) and 71 as benign (56 cellular, 15 paucicellular). The presence of desmin was detected in benign mesothelial cells in 47 of 56 (84%) reactive cellular specimens compared with 1 of 12 (8%) malignant mesotheliomas and 2 of 98 (2%) carcinomas. N-cadherin was expressed in 48 of 56 (86%) reactive cases, 12 of 12 (100%) mesotheliomas, and 47 of 98 (48%) carcinomas. In carcinomas, N-cadherin expression was most often seen in ovarian carcinoma but was also found in other carcinomas. Calretinin, an established marker of mesothelial cells, was detected in 52 of 56 (93%) reactive specimens, 11 of 12 (93%) mesotheliomas, and 3 of 98 (3%) carcinomas. Evaluation of staining results led to reclassification of six malignant specimens as benign, whereas 17 cases diagnosed as benign and the two diagnosed as inconclusive were classified as malignant. In conclusion, desmin appears to be a promising marker for the distinction between reactive mesothelium and malignant epithelial cells in terms of both specificity and sensitivity, and its complementary use with calretinin is recommended. Unlike calretinin, it may also prove valuable for the distinction between benign and malignant mesothelial cells. N-cadherin does not have a role in the distinction between mesothelial and epithelial cells. However, it may prove useful in the characterization of carcinomas of unknown origin. As has previously been shown, a significant number of diagnoses that are based on morphologic examination alone are modified after the use of a broad antibody panel.American Journal of Surgical Pathology 12/2001; 25(11):1405-12. · 4.87 Impact Factor