Neuropathology
Maryam Mohebbi; Mansoureh Shokripour; Maral Mokhtari
Abstract
Background & Objective: Brain tumors are the most frequent solid tumors in children. High-grade tumors are more challenging in diagnosis. Atypical teratoid rhabdoid tumor (ATRT) may be mistaken for other high-grade brain tumors. Molecular genetic analysis of ATRT has shown deletion and mutation in ...
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Background & Objective: Brain tumors are the most frequent solid tumors in children. High-grade tumors are more challenging in diagnosis. Atypical teratoid rhabdoid tumor (ATRT) may be mistaken for other high-grade brain tumors. Molecular genetic analysis of ATRT has shown deletion and mutation in the hSNF5/INI1 gene in most of the cases. The INI1 protein expression can be helpful for the accurate diagnosis.Methods: In this study, immunohistochemical staining (IHC) using INI1 antibody was performed to determine the possibility of ATRT misdiagnosis. Totally, 147 tumors including 6 ATRTs, 81 medulloblastomas, and 60 other CNS tumors were examined in children between 0 and 17 years old.Results: No nuclear staining was found in the six ATRT cases, while most of other CNS tumors demonstrated nuclear staining. Five cases were previously diagnosed with medulloblastoma, primitive neuroectodermal tumor (PNET), and anaplastic oligodendroglioma, while the diagnoses were changed to ATRT based on the re-evaluation of the H&E slides and INI1 study. Additionally, two cases were recurrent tumors whose features were consistent with those of ATRT. The INI1 immunostaining was negative in these cases.Conclusion: INI1 was very helpful in distinguishing ATRT from its mimickers in challenging cases. All known ATRT cases in this study were immunonegative for INI1. Thus, INI1 is recommended to be used in the initial IHC panel for the high-grade brain tumors, especially in children under the age of three years, so that they can benefit from intensified therapeutic regimens.
Hematopathology
Mohammad Hadi Sadeghian; Zahra Rezaei dezaki
Volume 13, Issue 3 , July 2018, , Pages 294-300
Abstract
Acute myeloid leukemia (AML) as a distortion of blood cells involves the differentiation of hematopoietic stem cells. Several studies established the irregular overexpression of specific genes is a common finding in patients with AML. The ectopic viral integration site-1 (EVI1) gene is a proto-oncogene ...
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Acute myeloid leukemia (AML) as a distortion of blood cells involves the differentiation of hematopoietic stem cells. Several studies established the irregular overexpression of specific genes is a common finding in patients with AML. The ectopic viral integration site-1 (EVI1) gene is a proto-oncogene subject to alternative splicing, and encodes a zinc-finger protein that acts as a transcriptional regulator in early development. Forced overexpression of EVI1 in hematopoietic progenitors later induced a myeloid differentiation block. The current review aimed at determining the prognostic value of EVI1 expression in patients with AML in the age range of one month to fifteen years. The scientific databases including PubMed, Google Scholar, EMBASE, Scopus, and ISI published up to January 2016 were searched using the conformity keywords and a total of four articles were studied. Three articles declared higher overexpression of EVI1 in patients with mixed-lineage leukemia (MLL) rearrangements. The percentage of overall survival (OS), reported in two articles, decreased in AML patients with high EVI1 expression. A study reported that the relationship between EVI1 expression and OS was negligible in cases with and without EVI1 expression. Another study showed significant differences in event free survival (EFS) and OS in the group of patients with positive MLL-AF9 between EVI1+ and EVI1- patients. The current study revealed that high EVI1 expression was not a poor prognostic factor in pediatric patients with AML. And this gene expression was mainly prognostic concomitantly by other factors such as MLL rearrangement, MEL1 expression, and white blood cell (WBC) count.
