A comparison of two techniques of cell block preparation

Background: Cell block technique is a method of preparing cytological material so that it can be processed, sectioned, stained, and viewed as a histology section. The study compared two methods of cell block preparation, plasma-thromboplastin method and collodion bag technique of cell block preparation. Materials and Methods: Samples were randomly processed by plasma-thromboplastin technique or by collodion bag technique. Hematoxylin/Eosin stained cell block sections were examined and scored scaling from 1 to 3 for cellularity, clarity, nuclear features, cytoplasm, use of ancillary test and recovery of cell-cluster and fragments. Mann-Whitney U test was used for comparing two methods and establishing statistical significance. Results: The median cellularity score was 2.0 for plasma-thromboplastin and 1.0 for collodion bag. The median morphological preservation score and use of ancillary test score were 2.0 for both of the method while median score for recovery of cell cluster and fragments was 2.0 for collodion bag and 1.0 for plasma-thromboplastin. Statistically, both of the methods had similar results in cell block quality. The median total score for plasma-thromboplastin and collodion bag were 10.0 and 11.0 respectively. Diagnostic cell blocks were obtained in 46.51% of cell block by plasma-thromboplastin method and 60.52% of cell block by collodion bag method improving the diagnosis over conventional smear in 76.74% and 81.57% respectively. Conclusions: Cell block by plasma-thromboplastin and collodion bag method are cost effective, useful adjunct to FNA for diagnosis of mass lesion. Both techniques has no significant difference in quality of cell block produced.

Corrigendum

Ong CB, Herdt TH, Fitzgerald SD. Hyperplastic goiter in two adult dairy cows. J Vet Diagn Invest 2014;26:810–814. (Original doi: 10.1177/1040638714554441). The use of mineral supplements as a top dressing and trace mineralized salt noted by the authors was based on non-documented verbal comments and not based on direct observation. Therefore, the definitive source of the excess iodine measured in the thyroid gland of the 2 cows examined was not identified. The acknowledgments for this case report have been revised to reflect appropriate contributors to the case. We thank Tom Wood and the Histology Section of the Diagnostic Center for Population and Animal Health (DCPAH) for technical assistance processing the slides of the cases in this report. We also thank Drs. Tim Lyons, Daron Jones, and James Averill for their contributions to this case.

Tanycytic Ependymoma: A Challenging Histological Diagnosis

Tanycytic ependymoma is a rare form of ependymoma that usually arises in the intramedullary spine. It has a unique histology emphasized by the inconspicuous ependymal pattern of cells and close resemblance to schwannoma and astrocytoma. The authors report a 50-year-old man with a cervical tanycytic ependymoma that was initially thought to be a schwannoma. The frozen histology section showed spindle cells with oval and elongated nuclei with occasional hemosiderin deposits present suggesting a preliminary diagnosis of schwannoma. Immunohistochemical staining of the permanent section revealed strong immunoreactivity for glial fibrillary acidic protein with intermittent S-100 positivity, confirming that the tumor was a tanycytic ependymoma. This underlines the challenges involved in making an accurate diagnosis and demonstrates that careful and detailed histological inspection with immunohistochemical stains and ultrastructural microscopy may be necessary to distinguish tanycytic ependymoma from other neoplasms.

Assessment of Structure Distortion of Paraffin Wax Histology Section of Human Carotid Atherosclerotic Plaque Specimen

Paraffin wax histology analysis is treated as a golden standard to verify biological tissue microstructure. To generate a histology section, the tissue is subject to a sequence of dehydration processes to remove water from the tissue and replace it by wax to maintain the internal tissue structure. This process normally generates significant shrinkage in the specimen [1], adding uncertainties on quantifying region sizes based on histology sections, such as the area of lipid region, fibrous cap thickness (FCT) in human arterial plaque specimens.

7. On the Cell-Walls of Hepatic Cells

Since Henle and Purkinje first described the cells which form the great mass of the liver, microscopists have maintained that these are what are termed “naked protoplasts”—that is, they possess, like the white blood corpuscle, no differentiated cell-walls. I may mention the names of Dr Lionel Beale, Ewald Hering (“Stricker's Histology,” section on the Liver), and Dr Klein (“Atlas of Histology”), who all agree in denying its existence. Indeed, the absence of this structure is emphatically insisted upon in most works on microscopical anatomy.If a liver-cell be examined with a power of about 300 diameters, it is seen to be a granular mass, of a somewhat spherical shape, containing a very distinct nucleus and nucleolus. The granules are but the optical expression of a delicate reticulum or stroma, which may be seen as such on using a higher power.