Application of the cell block method, utilizing mount quick mounting medium

Our objective was to determine the applicability of cell transfer and cell block methods using Mount Quick (Daido Sangyo, Saitama, Japan) mounting medium (MQ) for hematoxylin-eosin (H&E) and immunohistochemical staining of several limited amounts of biological materials in slide preparations. The materials investigated were histopathologically confirmed malignant mesotheliomas (pleural effusions) and malignant lymphomas, a malignant melanoma, and an amelanotic melanoma in sealed slides. Monoclonal antibodies against carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), cancer antigen 125 (CA-125), vimentin, thrombomodulin (TM), cytokeratin, UCHL-1, L-26, melanoma-specific antigen (HMB45), and S-100 protein (S-100) were applied in the investigation. The malignant mesotheliomas were found to be positive for EMA, cytokeratin, vimentin, TM, and CA-125, and negative for CEA, with no differences being observed in findings from direct contact preparations. Using T-cell-type malignant lymphomas for immunohistochemistry, UCHL-1 positivity and L-26 negativity were clearly demonstrated. The malignant melanoma and amelanotic melanoma materials stained strongly for HMB45 and S-100. Cell transfer employing MQ is a suitable approach for immunohistochemical investigations of limited materials. In addition, cell blocks derived from MQ-embedded smears can be used for both H&E and immunohistochemical staining. Diagn. Cytopathol. 2000;22:117-119.