| Written | 2005-01 | Cristina Morerio, Claudio Panarello |
| Dipartimento di Ematologia ed Oncologia Pediatrica, IRCCS Istituto Giannina Gaslini, Largo G. Gaslini 5, 16147 Genoa, Italy |
| Identity |
| ICD-Topo | C470-C476,C478-C479,C490-C496,C498-C499 CONNECTIVE & SOFT TISSUE |
| ICD-Morpho | 8881/0 Lipoblastoma / Lipoblastomatosis |
| Atlas_Id | 5155 |
| Phylum | Soft Tissues::Lipoblastoma |
| WHO/OMS Classification | Soft Tissues |
| Classification |
| Two forms of the tumor lesion have been described: encapsulated circumscribed type (lipoblastoma), and a noncapsulated diffuse infiltrative type (lipoblastomatosis). |
| Clinics and Pathology |
| Disease | Benign uncommon soft-tissue tumor of embryonal fat. |
| Embryonic origin | Develops from embryonic remnants of white fat tissue. |
| Epidemiology | Primarily occurs in young children (<3 years) prevalently male. |
| Clinics | Presents in superficial tissues of arms and legs (deeper in lipoblastomatosis), though mediastinum, retroperitoneum, trunk, head and neck may be affected. |
| Pathology | Lobulated tissue composed of immature fat cells separated by fibro-vascular septa and areas with a myxoid matrix. The lobules contain lipoblasts in different stages of differentiation, ranging from primitive, spindle-shaped cells to lipoblasts simulating mature fat cells. Differential diagnosis, particularly in older children or in diffuse lipoblastoma, include myxoid liposarcoma and atypical lipoma and may be based on distinct cytogenetic abnormalities. |
| Treatment | Surgical excision. |
| Prognosis | These tumors have an excellent prognosis but local recurrence is possible expecially in diffuse lesions. |
| Cytogenetics |
| Cytogenetics Morphological | Pseudodiploid karyotype with clonal chromosomal rearrangements involving the 8q11-13 region. Gain of chromosome 8 is reported. |
| Cytogenetics Molecular | Detectable by metaphase and/or interphase FISH using specific PLAG1 probes. |
 | |
| Dual-color FISH analysis in a case of lipoblastoma with complex structural rearrangement: RP11-140I16 (PLAG1) (red) was cohybrized with RP11-299N14 (HAS2) (green). Arrow indicates PLAG1-HAS2 fusion signal on the der(8), arrowhead indicates the normal chromosome 8. The BAC clones were provided by Prof. M.Rocchi. | |
| Probes | RP11-140I16, BAC227k20, YAC164H5, RP11-299N14, YAC947h7. |
| Genes involved and Proteins |
| Gene Name | PLAG1 (Pleomorphic adenoma gene 1) |
| Location | 8q12.1 |
| Dna / Rna | 7313 bp mRNA |
| Protein | PLAG1, (together with PLAGL1 and PLAGL2), belongs to a subfamily of C2H2 zinc finger transcription factors that activate transcription. |
| Gene Name | HAS2 (hyaluronan synthase 2) |
| Location | 8q24.13 |
| Gene Name | COL1A2 (collagen, type I, alpha 2) |
| Location | 7q21.3 |
| Result of the chromosomal anomaly |
| Hybrid Gene | |
| Note | HAS2-PLAG1, COL1A2-PLAG1 Chromosomal rearrangements in tumor tissue determine PLAG1 transcriptional up-regulation. |
| Description | The 8q12 rearrangement results in a promoter-swapping event, whereby the PLAG1 promoter element is replaced by promoting regions from other genes, notably hyaluronic acid synthase 2 (HAS2) or collagen 1 a 2 (COL1A2). 5' HAS2 - 3' PLAG1 fused after an 8q intrachromosomal rearrangement that determined the juxtaposition of band 8q12.1 to 8q24.1. The breakpoint of HAS2 gene is in intron 1, whereas its coding sequence starts at the first codon of exon 2. 5' COL1A2 - 3' PLAG1 has been described in one case of t(7;8)(p22;q13) |
| Transcript | Alternative splicing variants which included or lacked PLAG1 exon 2. |
| Fusion Protein | |
| Description | HAS2-PLAG1 and COL1A2-PLAG1 both encode a full-lenght PLAG1 protein. |
| Bibliography |
| Evidence of involvement of the PLAG1 gene in lipoblastomas. |
| Astrom A, D'Amore ES, Sainati L, Panarello C, Morerio C, Mark J, Stenman G |
| International journal of oncology. 2000 ; 16 (6) : 1107-1110. |
| PMID 10811981 |
| Evidence by spectral karyotyping that 8q11.2 is nonrandomly involved in lipoblastoma. |
| Chen Z, Coffin CM, Scott S, Meloni-Ehrig A, Shepard R, Issa B, Forsyth DR, Sandberg AA, Brothman AR, Lowichik A |
| The Journal of molecular diagnostics : JMD. 2000 ; 2 (2) : 73-77. |
| PMID 11272891 |
| Benign lipoblastomatosis. An analysis of 35 cases. |
| Chung EB, Enzinger FM |
| Cancer. 1973 ; 32 (2) : 482-492. |
| PMID 4353020 |
| PLAG1 alterations in lipoblastoma: involvement in varied mesenchymal cell types and evidence for alternative oncogenic mechanisms. |
| Gisselsson D, Hibbard MK, Dal Cin P, Sciot R, Hsi BL, Kozakewich HP, Fletcher JA |
| The American journal of pathology. 2001 ; 159 (3) : 955-962. |
| PMID 11549588 |
| Lipoblastoma and lipoblastomatosis: a report of two cases and review of the literature. |
| Harrer J, Hammon G, Wagner T, Bolkenius M |
| European journal of pediatric surgery : official journal of Austrian Association of Pediatric Surgery ... [et al] = Zeitschrift fur Kinderchirurgie. 2001 ; 11 (5) : 342-349. |
| PMID 11719876 |
| PLAG1 fusion oncogenes in lipoblastoma. |
| Hibbard MK, Kozakewich HP, Dal Cin P, Sciot R, Tan X, Xiao S, Fletcher JA |
| Cancer research. 2000 ; 60 (17) : 4869-4872. |
| PMID 10987300 |
| Atypical lipomatous tumor in a 14-year-old patient: distinction from lipoblastoma using FISH analysis. |
| Kuhnen C, Mentzel T, Fisseler-Eckhoff A, Debiec-Rychter M, Sciot R |
| Virchows Archiv : an international journal of pathology. 2002 ; 441 (3) : 299-302. |
| PMID 12242528 |
| PLAG1-HAS2 fusion in lipoblastoma with masked 8q intrachromosomal rearrangement. |
| Morerio C, Rapella A, Rosanda C, Tassano E, Gambini C, Romagnoli G, Panarello C |
| Cancer genetics and cytogenetics. 2005 ; 156 (2) : 183-184. |
| PMID 15642402 |
| Lipoblastoma: a case with t(7;8)(q31;q13). |
| Panarello C, Rosanda C, Morerio C, Russo I, Dallorso S, Gambini C, Ricco AS, Storlazzi T, Archidiacono N, Rocchi M |
| Cancer genetics and cytogenetics. 1998 ; 102 (1) : 12-14. |
| PMID 9530333 |
| Updates on the cytogenetics and molecular genetics of bone and soft tissue tumors: lipoma. |
| Sandberg AA |
| Cancer genetics and cytogenetics. 2004 ; 150 (2) : 93-115. |
| PMID 15066317 |
| Chromosome abnormalities in two benign adipose tumors. |
| Sandberg AA, Gibas Z, Saren E, Li FP, Limon J, Tebbi CK |
| Cancer genetics and cytogenetics. 1986 ; 22 (1) : 55-61. |
| PMID 3456828 |
| Citation |
| This paper should be referenced as such : |
| Morerio, C ; Panarello, C |
| Soft tissue tumors: Lipoblastoma |
| Atlas Genet Cytogenet Oncol Haematol. 2005;9(1):56-57. |
| Free journal version : [ pdf ] [ DOI ] |
| On line version : http://AtlasGeneticsOncology.org/Tumors/LipoblastomaID5155.html |
| Translocations implicated (Data extracted from papers in the Atlas) |
| del(8)(q12q24) HAS2/PLAG1 | |
| t(7;8)(q31;q12) COL1A2/PLAG1 | |
| t(8;14)(q12;q24) RAD51B/PLAG1 | |
| External links |
| REVIEW articles | automatic search in PubMed |
| Last year articles | automatic search in PubMed |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Wed Nov 28 16:26:04 CET 2018 |
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