title: Resolving quandaries: basaloid adenoid cystic carcinoma or breast cylindroma? The role of massively parallel sequencing.
abstract: OBJECTIVE
  The aims of this study were to perform a whole-exome sequencing analysis of a breast cylindroma and to investigate the role of molecular analyses in the differentiation between breast cylindroma, a benign tumour that displays MYB expression, and CYLD gene mutations, and its main differential diagnosis, the breast solid-basaloid adenoid cystic carcinoma, a malignant tumour that is characterized by the presence of the MYB-NFIB fusion gene and MYB overexpression.
  
  
  RESULTS
  A 66-year-old female underwent quadrantectomy after an irregular dense shadow was discovered in the right breast at the screening mammogram. Histologically, the tumour displayed features suggestive of a solid-basaloid variant of adenoid cystic carcinoma with a differential diagnosis of cylindroma. Fluorescence in situ hybridization, reverse transcription-polymerase chain reaction, immunohistochemistry and whole-exome sequencing revealed absence of the MYB-NFIB fusion gene, low levels of MYB protein expression and a clonal somatic CYLD splice site mutation associated with loss of heterozygosity of the wild-type allele.
  
  
  CONCLUSIONS
  The results of the histological, immunohistochemical and molecular analyses were consistent with a diagnosis of breast cylindroma, providing a proof-of-principle that the integration of histopathological and molecular approaches can help to differentiate between a low-malignant potential and a benign breast tumour of triple-negative phenotype.
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.|School of Pathology, University of Milan, Milan, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Fusco
authors.affiliation: Department of Surgical Oncology, Montpellier Cancer Institute (ICM), Montpellier, France.
authors.forename: Pierre-Emmanuel
authors.initials: PE
authors.lastname: Colombo
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Luciano G
authors.identifier: http://orcid.org/0000-0002-9625-1183
authors.initials: LG
authors.lastname: Martelotto
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Maria R
authors.initials: MR
authors.lastname: De Filippo
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Piscuoglio
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Charlotte K Y
authors.initials: CK
authors.lastname: Ng
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Raymond S
authors.initials: RS
authors.lastname: Lim
authors.affiliation: Department of Surgical Oncology, Montpellier Cancer Institute (ICM), Montpellier, France.
authors.forename: William
authors.initials: W
authors.lastname: Jacot
authors.affiliation: Department of Tumor Biology, Institut Curie, Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Vincent-Salomon
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Jorge S
authors.initials: JS
authors.lastname: Reis-Filho
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Britta
authors.initials: B
authors.lastname: Weigelt
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000601:surgery; D003528:Carcinoma, Adenoid Cystic / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000601:surgery; D059472:Exome / Q000235:genetics; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D015412:Mastectomy, Segmental; D010641:Phenotype; D017422:Sequence Analysis, DNA
chemical_list: D014408:Biomarkers, Tumor
keywords: adenoid cystic carcinoma; breast cancer; cylindroma; fluorescence in-situ hybridization; massively parallel sequencing