Fluorescence in situ hybridization (FISH) has revolutionized molecular cytogenetic analysis since the 1980s, enabling precise localization of DNA sequences in cells and tissues. Despite its relevance, applying FISH to formalin-fixed paraffin-embedded (FFPE) tissue samples encounters significant technical challenges. This review addresses the main issues encountered in this context, such as inadequate fixation, contamination, block and slide age, inadequate pretreatment, and FISH technique.
View Article and Find Full Text PDFThe beginning of post-mortem evaluation studies through minimally invasive procedures began between 1800 and 1930. It started with Dr. Howard Kelly and was later followed by Décio Parreiras and Werneck Genofre, due to the yellow fever outbreak in Brazil.
View Article and Find Full Text PDFActa Cir Bras
December 2023
Purpose: To determine molecular events involved in the tumorigenesis of phyllodes tumors (PT) and the role of each stromal (SC) and epithelial (EC) cell.
Methods: Frozen breast samples enriched with epithelial and stromal cells from three fibroadenomas and 14 PT were retrieved and laser microdissected. Sanger and polymerase chain reaction-based sequencing of exon 2 MED12 and TERT promoter hotspot mutations were performed; 44K microarray platform was used to analyze gene expression.
Pilocytic astrocytoma is the most common primary CNS neoplasm in children and adolescents, rare after the first two decades of life. While some authors report a favorable prognosis in the adult age group with the tumor, others have associated it with higher mortality. The molecular alteration most observed in cases of pilocytic astrocytoma in the pediatric group is the BRAF-KIAA1549 gene fusion, and there are still few studies confirming the presence of this fusion in the adult population.
View Article and Find Full Text PDFPurpose: We evaluated the immunoexpression of potential markers involved in the HER2 pathway in invasive breast carcinoma with HER2 amplification treated with trastuzumab.
Methods: Samples of ninety patients diagnosed and treated at two public Brazilian hospitals with overexpressed invasive carcinoma between 2009 and 2018 were included. Several markers (Bcl-2, CDK4, cyclin D1, EGFR, IGF1, IGF-1R, MDM2, MUC4, p16, p21, p27, p53, PTEN, RA, TNFα, and VEGF) were immune analyzed in the tumor by immunohistochemistry and then correlated with clinicopathological variables.