Pathology

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Browsing Pathology by Author "Bekuretsion Yonas"

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    Comparison of Modified Papanicolaou and Dane-Herman Stain with Routine Hematoxylin and Eosin Stain for Demonstration of Keratin in Tissue Sections
    (Addis Ababa University, 2019-04) Sori Moti; Bekuretsion Yonas; Girma Yonas
    Background: Keratins are intermediate filament forming proteins with specific physicochemical properties produced in any vertebrate epithelia. Having characteristic findings in many epithelial pathologies made them diagnostically important marker. Hematoxylin and Eosin(HE) stain, the routine dye, does not distinguish different eosinophilic components of connective tissue distinctly. On the other hand, special stains like modified Papanicolaou( Mod Pap) and Dane-Herman(D-H) stain can prove to be a simple solution to detect the presence and pattern of keratin histologically. Objectives: To compare modified Papanicolaou stain and Dane Herman stain with routine Hematoxylin and Eosin Stain for demonstration of keratin and also there basic staining characteristics on paraffin blocks tissue sections. Methodology: A total of 116 Formalin-Fixed Paraffin-Embedded(FFPE) tissue blocks were taken of known keratin containing tissue which included Squamous Cell Carcinoma(SCC), Squamous Papilloma, Verrucous Carcinoma and Odontogenic Keratocyst. The tissue blocks were retrieved from the archive of Tikur Anbessa Specialized Hospital(TASH), Department of Pathology. Three sections of 4µm thick tissue from each paraffin block were made and stained with HE, Mod PAP and D-H stains. Then the three stains were evaluated for Nuclear stain(NS), Cytoplasmic stain(CS), Uniformity of staining(US), Background stain(BS) and Keratin pattern(KP) by two pathologists. Finally, the third Senior pathologist was used as a tie breaker. Result: Mod PAP showed agreement with HE by showing Mc Nemar’s P value of 0.219 for NS, 0.727 for CS, 0.851 for US, 0.824 for BS and 1.00 for KP. Whereas D-H showed disagreement with HE for the first four parameters(P=0.000). But D-H showed agreement for KP. Thus, these results show that keratin was stained by D-H, Mod PAP and HE stains distinctly. Mod PAP stain showed similar result when compared with HE stain with parameters-NS, CS, US and BS. However, D-H stain showed statistically significant difference when crosschecked with HE stains. Special stains agreement were analyzed using McNemar as a statistical data tool, P< 0.05 were considered statistically significant. Conclusion: Mod PAP and D-H stains showed similar result for staining of keratin compared to HE stain. For the other four parameters Mod PAP showed an excellent result but not D-H.
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    Evaluating Efficacy of Paraffin Oil, Isopropanol and Ethanol Mixture as Alternative for Xylene in Surgical Biopsy Tissue Processing by the Conventional Paraffin Wax Method: Comparative Study in Histopathology
    (Addis Ababa University, 2021-06) Berhane Natinael; Bekuretsion Yonas; Abite Yeshiwas
    Background: Major global mortality is due to non-communicable diseases with cancer predominance. Unfortunately, Cancers diagnosed at late to end stages in Africa. Histopathology diagnosis has tremendous value in the treatment, prognosis and follow up of cancer patients. Fixation, processing, embedding, sectioning, staining and evaluation of slides are mandatory procedures in histopathology. These procedures use noxious and carcinogenic chemicals primarily xylene. However; xylene is hazardous chemical that causes muscular, neuron, ocular, reproductive, respiratory, immunological, hematological, renal, hepatic, cardiac effects. Fluid and vapors of xylene cannot be prevented with glove and masks. Hence there should be some substitution mechanism which can minimize or replace use of xylene in histopathology laboratory. Objective: This study aimed to evaluate the comparative efficacy of paraffin oil, isopropanol and ethanol mixture (PIE) as a bio friendly replacement for noxious xylene in surgical tissue processing with conventional paraffin wax method. Method: Prospective cross-sectional method and purposeful sampling technique was used at St. Paul’s hospital millennium medical college pathology department from February 2019 up to December 2020 GC. A total of 112 samples were processed using new mixture and conventional xylene method. Block sectioning simplicity and slide quality for diagnosis were evaluated by histologists and pathologists using standard checklist respectively. Result: According to the study, report of the three histologists revealed that 94.4% and 94.5% blocks were easy to produce good sections with paraffin oil, isopropanol and ethanol mixture and Conventional xylene methods respectively; indicating no statistical difference among methods (p=0.967). Evaluation of mounting, block storage stability and physical quality of sections confirmed adequacy in 98.2%, 99.1% and 98.3% respectively. This result showed no statistical significant difference with the conventional method (p=1.000)). The new xylene free method showed 95 % and 96.4% nuclear and cytoplasmic staining adequacy respectively.no statistical difference in both parameters recorded (p=0.602 and0.772 respectively) 95.3%, 96.8% and 95.5 % of stained slides which were processed with the new method revealed adequacy for clarity, uniformity and crispness of staining respectively indicating no statistical significant difference as p=0.073, 0.108, and 0.180 respectively. About 95.8% of total slides were adequate for diagnosis with the new method which was not statistically significant (p=0.668 & p= 0.229 by score and observant respectively). Conclusion: The new mixture has comparable ability with that of xylene to clear surgical biopsy specimens during processing in histopathology.