Improvements in cell block processing: The Cell-Gel method

BACKGROUNDThe ability to produce adequate cell blocks profoundly impacts the diagnostic usefulness of cytology specimens. Cell blocks are routinely processed from fine-needle aspiration specimens or concentrated fluid samples. Obtaining directed passes for the sole purpose of producing a cell block is common practice, particularly when the cytopathologist anticipates the need for ancillary immunocytochemical stains and/or molecular studies. METHODSThe authors developed an effective and inexpensive process for producing cell blocks that consistently yields abundant cellular material, which they have termed the Cell-Gel method. This method can be simplified into 3 main steps: 1) preparing the sample; 2) constructing the cell block; and 3) processing the cell block. Highlights of the protocol include using a hemolytic fixative for sample preparation and disposable base molds for cell block construction. RESULTSThe cell block failure rate in the current study decreased from 18% with the HistoGel Tube method (January 2014-December 2014) to 6% with the Cell-Gel method (January 2015-December 2016). The authors evaluated 110 cell blocks processed with the HistoGel Tube method and 110 cell blocks processed with the Cell-Gel method, for a total evaluation of 220 cell blocks. CONCLUSIONSThe authors have developed an effective and inexpensive protocol for producing cell blocks that consistently yields abundant cellular material. The Cell-Gel method uses a hemolytic fixative and disposable base molds to produce adequate cell blocks. When the method was implemented, the cell block failure rate of the study laboratory decreased by approximately 67%. Cancer Cytopathol 2017;125:267-276. (c) 2016 American Cancer Society. Cell blocks are routinely processed from fine-needle aspiration specimens or concentrated fluid samples. The authors have developed an effective and inexpensive process for producing cell blocks that consistently yields abundant cellular material.