Immunocytochemistry in effusion cytology

Abstract

METHODS.The authors review the most commonly used cytologic preparations, fixatives, and antibodies used in effusion ICC. RESULTS.Through the utilization of cell block preparations and a panel of antibodies appropriate for the differential diagnosis in question, ICC conditions utilized in surgical pathology can be most closely replicated. CONCLUSIONS. ICC may provide reliable insights into various diagnostic dilemmasin effusion cytology, provided that laboratory standardization practices are fol- Some of the greatest diagnostic dilemmas in cytopathology are in the realm of effusion cytology. Hyperplastic mesothelial cells observed in various benign conditions can undergo cytologic alterations, mimicking malignant cells. [1][2][3][4] Extensive morphologic overlap also exists between malignant mesothelial cells and metastatic carcinoma cells. [1][2][3][4] In many cases, a definitive diagnosis cannot be reached based on morphology alone; thus, the diagnostic accuracy of effusion cytology is enhanced though the utilization of ancillary techniques.Electron microscopy has long been considered the "gold standard" for the diagnosis of malignant mesothelioma (MM) through the demonstration of numerous long, complex microvilli. Unfortunately, microvilli can vary in length and number from tumor-to-tumor as well as within a tumor, and the presence of short microvilli does not always exclude a diagnosis of MM. Currently, immunohistochemical stains that are widely utilized as diagnostic discriminators for the aforementioned diagnoses recognize both epithelial-derived and mesothelial cells. The seminal studies outlining the sensitivity and specificity of these antibodies were performed on formalin fixed, paraffin embedded surgical pathology specimens. However, large-scale cytology studies evaluating the same antibodies for use in effusion cytology have been performed on a myriad of preparations (i.e., ethanol-fixed smears and cytospins, ThinPrep [Cytyc Corporation, Boxbourough, MA] preparations, airdried cytospins, and formalin fixed cell blocks), thus accounting for less than reliable and reproducible results. In addition, a wide variety of opinions exist among pathologists with regard to the relative effectiveness of some markers used for this differentiation. In keeping with the contemporary viewpoint that the standardization of immunohistochemical methods is essential for reliable and reproducible results, we present what we have found to be the optimal approach for the utilization of immunohistochemistry in effusion cytology, a view that we believe approximates the current procedures utilized in surgical pathology samples most closely. 6 -9 In our experience, participation in the College of American Pathologists laboratory inspection and proficiency testing programs has contributed greatly to improving our immunocytochemistry (ICC) services, moving them toward a higher degree of standardization. -9 Specimen ProcessingTo achieve optimal specimen processing for ICC, effusion samples should be received in the cytology labor...

Comprehensive genetic and functional characterization of IPH‐926: a novel CDH1‐null tumour cell line from human lobular breast cancer

“…IPH-926 expressed the epithelial cell markers TACSTD1/Ep-CAM, KRT18, and KRT19 at the mRNA as well as at the protein level ( Figures 1C-1F). In contrast, IPH-926 entirely lacked mRNA expression of the mesothelial cell marker CALB2 and of the B-lymphoblastoid cell marker BLAST1 [40,41] (Figure 1C). Moreover, IPH-926 cells completely lacked mRNA expression of ESR1, encoding for ER; CDH1, encoding for E-cadherin; and CTNNB1, encoding for β-catenin ( Figures 1C and 1D).…”

The β subunit of human chorionic gonadotropin lacks specificity for malignant cells in serous effusions

“…(12) 6 (50) 5 (42) Lung (9) 7 (78) 4 (44) Ovary (3) 2 (67) 0 Other (7) 2 (29) 2 (29) Unknown (13) 11 (85) 9 (69) Mesothelioma (4) 2 (50) 0 Neuroendocrine (1) 0 0 Squamous cell (1) 0 0…”

“…Immunocytochemistry has been studied extensively as a means of resolving this diagnostic dilemma, but there is no consensus regarding an optimal staining combination. [1][2][3][4] HCG is a hormone expressed in large quantities in human placenta. Use of hCG as a laboratory test for diagnosing pregnancy, screening for trophoblastic disease and germ cell tumors is well established.…”

“…To date, no consensus has been reached in this regard. [1][2][3][4] b-human chorionic gonadotropin (hCG) is a hormone normally expressed in human placenta and trophoblastic tumors. Several carcinomas, in addition to trophoblastic tumors, may express hCG, and detection of serum hCG in patients with such carcinomas generally portends a poor prognosis.…”

The reactivity to CK5/6 antibody in tumor cells from non-small cell lung cancers shed into pleural effusions predicts survival

“…Immunocytochemistry is a widely used tool to characterize malignant cell populations in effusions (11)(12)(13). Adenocarcinomas and large cell carcinomas of the lung both tend to spread to the pleural cavities and cannot always be distinguished morphologically when they appear in effusions.…”