Modern Techniques in Cytopathology. Группа авторов. Читать онлайн. Newlib. NEWLIB.NET

Автор: Группа авторов
Издательство: Ingram
Серия: Monographs in Clinical Cytology
Жанр произведения: Биология
Год издания: 0
isbn: 9783318065763
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      Cell-Gel, a recent modification of the HistoGel method, is another economical solution with a decreased reported failure rate [9] when compared to traditional HistoGel cell blocks. Briefly, after a sample is mixed with a hemolytic agent to lyse red blood cells, it is centrifuged, and the supernatant then discarded. The remaining concentrate is transferred into an appropriate-sized disposable mold used during tissue embedding in histology. HistoGel is subsequently added and the assembly is cooled until it has solidified. The solidified pellet is removed from the mold and positioned in a cassette lined by foam, while maintaining its original orientation in the mold, and the Cell-Gel-containing cassette is placed in the tissue processor. The boundaries and flat bottom of the mold allow the cells to distribute evenly in a restricted area along the bottom. Also, preserving the orientation at the time of embedding encourages sectioning of the cellular side first; however, caution has to be exercised to avoid inadvertently trimming off too much tissue from the block. Because a hemolytic agent (e.g., CytoRich Red), which contains alcohols, is used instead of formalin, validation to ensure compatibility with IHC has to be performed.

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      Cell Blocks: Application to Modern and Alternative Techniques

      Clinicians and cytologists are sometimes faced with cytology samples that are non-diagnostic or inadequate for ancillary testing, which hinders appropriate patient management. This may result from various factors, including the nature of the lesion targeted for FNA, operator skill, and inadequate cellularity on the cell block. To improve the diagnostic yield, manufacturers of needles, especially for endoscopic ultrasound-guided procedures, have developed larger-gauge needles with new needle tip designs that extract “micro-cores.” The procedure and sample represent a hybrid – the motion to obtain the tissue fragments is the same as FNA biopsies, yet the needle size and design produce a “micro-core.” These samples typically contain mini tissue fragments in a core-shaped fragment of partially clotted blood. These FNA-derived micro-core biopsies represent a cross-roads between cytology and histology. There is some debate regarding the best method and laboratory ideally equipped to manage such specimens – either as cytology cell blocks or as histology biopsies. Since these samples, in addition to having visible tissue fragments, also contain cells dispersed in blood and liquid media, they are better managed by cytology procedures that will capture all of the cells by centrifugation