title: Biphasic, hyperdiploid breast tumors in children:  a distinct entity?
abstract: BACKGROUND
  The differentiation between a giant fibroadenoma and a phyllodes tumor can be a precarious diagnostic task. However, the distinction between the 2 lesions is important to make, especially since the latter can be malignant and consequently the prognoses differ.
  
  
  METHODS
  We used various genetic approaches to study a breast tumor showing features of both entities in a 10-year-old girl with a congenital cerebral malformation and diabetes mellitus.
  
  
  RESULTS
  Cytogenetic analysis of cultured tumor cells from 3 different samples revealed a hyperdiploid karyotype: 50-54,XX,+5,+13,+17,+18,+19,+20,+21. High-resolution single nucleotide polymorphism array analysis not only confirmed the trisomies, but also revealed uniparental disomy (UPD) for chromosomes 10, 11, and 22. A consequence of UPD11 was a homozygous deletion in chromosome band 11p15 affecting the PARVA gene; this gene was hemizygously lost in constitutional DNA. Extended analysis of the family revealed that the deletion was inherited, but it did not segregate with breast tumors or congenital malformations.
  
  
  CONCLUSIONS
  Combined with the literature data, the findings in the present case strongly suggest that biphasic tumors with high hyperdiploid karyotypes constitute a distinct clinicomorphologic subgroup of benign breast tumors, being particularly common among young children.
authors.affiliation: Department of Clinical Genetics, University and Regional Laboratories, Skåne University Hospital, Lund University, Lund, Sweden. charles.walther@med.lu.se
authors.forename: Charles
authors.initials: C
authors.lastname: Walther
authors.forename: David
authors.initials: D
authors.lastname: Gisselsson
authors.forename: Linda
authors.initials: L
authors.lastname: Magnusson
authors.forename: Jenny
authors.initials: J
authors.lastname: Nilsson
authors.forename: Dorthe
authors.initials: D
authors.lastname: Grabau
authors.forename: Carl-Magnus
authors.initials: CM
authors.lastname: Kullendorff
authors.forename: Karolin H
authors.initials: KH
authors.lastname: Nord
authors.forename: Fredrik
authors.initials: F
authors.lastname: Mertens
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics; D002648:Child; D002869:Chromosome Aberrations; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis* / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D007621:Karyotyping; D008840:Microfilament Proteins / Q000235:genetics; D003557:Phyllodes Tumor / Q000175:diagnosis* / Q000235:genetics; D011003:Ploidies; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011379:Prognosis; D024182:Uniparental Disomy; D000096985:Calponins
chemical_list: D008840:Microfilament Proteins; C486590:PARVA protein, human; D000096985:Calponins