Novel insights into the BAP1-inactivated melanocytic tumor
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11140%2F22%3A10451289" target="_blank" >RIV/00216208:11140/22:10451289 - isvavai.cz</a>
Alternative codes found
RIV/61988987:17110/22:A2402NZE
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=HP2NxfWm8m" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=HP2NxfWm8m</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1038/s41379-021-00976-7" target="_blank" >10.1038/s41379-021-00976-7</a>
Alternative languages
Result language
angličtina
Original language name
Novel insights into the BAP1-inactivated melanocytic tumor
Original language description
BAP1-inactivated melanocytic tumor (BIMT) is a group of melanocytic neoplasms with epithelioid cell morphology molecularly characterized by the loss of function of BAP1, a tumor suppressor gene located on chromosome 3p21, and a mutually exclusive mitogenic driver mutation, more commonly BRAF. BIMTs can occur as a sporadic lesion or, less commonly, in the setting of an autosomal dominant cancer susceptibility syndrome caused by a BAP1 germline inactivating mutation. Owing to the frequent identification of remnants of a conventional nevus, BIMTs are currently classified within the group of combined melanocytic nevi. "Pure" lesions can also be observed. We studied 50 BIMTs from 36 patients. Most lesions were composed of epithelioid melanocytes of varying size and shapes, resulting extreme cytomorphological heterogeneity. Several distinctive morphological variants of multinucleated/giant cells were identified. Some hitherto underrecognized microscopic features, especially regarding nuclear characteristics included nuclear blebbing, nuclear budding, micronuclei, shadow nuclei, peculiar cytoplasmic projections (ant-bear cells) often containing micronuclei and cell-in-cell structures (entosis). In addition, there were mixed nests of conventional and BAP1-inactivated melanocytes and squeezed remnants of the original nevus. Of the 26 lesions studied, 24 yielded a BRAF mutation, while in the remaining two cases there was a RAF1 fusion. BAP1 biallelic and singe allele mutations were found in 4/22 and 16/24 neoplasms, respectively. In five patients, there was a BAP1 germline mutation. Six novel, previously unreported BAP1 mutations have been identified. BAP1 heterozygous loss was detected in 11/22 lesions. Fluorescence in situ hybridization for copy number changes revealed a related amplification of both RREB1 and MYC genes in one tumor, whereas the remaining 20 lesions studied were negative; no TERT-p mutation was found in 14 studied neoplasms. Tetraploidy was identified in 5/21 BIMTs. Of the 21 patients with available follow-up, only one child had a locoregional lymph node metastasis. Our results support a progression of BIMTs from a conventional BRAF mutated in which the original nevus is gradually replaced by epithelioid BAP1-inactivated melanocytes. Some features suggest more complex underlying pathophysiological events that need to be elucidated.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
30109 - Pathology
Result continuities
Project
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Continuities
S - Specificky vyzkum na vysokych skolach
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Modern Pathology
ISSN
0893-3952
e-ISSN
1530-0285
Volume of the periodical
35
Issue of the periodical within the volume
5
Country of publishing house
US - UNITED STATES
Number of pages
12
Pages from-to
664-675
UT code for WoS article
000725380800001
EID of the result in the Scopus database
2-s2.0-85120621097