Published in:
01-07-2020 | Original Article
Leiomyoma with Bizarre Nuclei: a Study of 108 Cases Focusing on Clinicopathological Features, Morphology, and Fumarate Hydratase Alterations
Authors:
Mária Gregová, Jan Hojný, Kristýna Němejcová, Michaela Bártů, Michal Mára, Barbora Boudová, Jan Laco, Lukáš Krbal, Ivana Tichá, Pavel Dundr
Published in:
Pathology & Oncology Research
|
Issue 3/2020
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Abstract
Leiomyoma with bizarre nuclei (LBN) is an uncommon variant of uterine smooth muscle neoplasm. Involvement of fumarate hydratase (FH) has been suggested in the pathogenesis of a subset of LBN. The goal of our study is to assess the clinicopathological, morphological, immunohistochemical and molecular findings focusing on FH in LBNs (n = 108) and compare it with the findings in usual leiomyomas (UL; n = 50) and leiomyosarcomas (LMS; n = 42). Immunohistochemically, loss of FH expression was found in 67/108 of LBN, 1/50 of UL and in no LMS. Class 4/5 FH mutations were detected in 15/53 LBN with sufficient DNA quality for molecular analysis. Pathogenic variants of the FH gene were detected in neither UL nor LMS. Local recurrence after surgery was present in 18/92 of LBN patients, 7 of which were histologically verified and 2 of which were found to be LBN. Our results confirmed that LBN behave in a benign fashion, although they may relapse. FH gene mutations were a common finding only in LBN, but not in UL and LMS. Immunohistochemistry with an antibody against FH seems to have a good sensitivity (87%) and moderate specificity (58%) with regard to predicting FH gene mutations and could be used as a screening method in tumors with features suggestive of FH alterations to identify patients who are at risk for the FH aberrations.