Lipoblastoma in adolescents and young adults: report of six cases with FISH analysis.
OBJECTIVE
Lipoblastoma is a rare benign adipocytic neoplasm that occurs primarily in infancy and early childhood. Histologically, there is some morphological overlap with atypical lipomatous tumour and myxoid liposarcoma and the age at presentation is often regarded as a major diagnostic criterion. However, we recently encountered several cases of lipoblastoma occurring in adolescents and young adults. The aim was to document the occurrence of lipoblastoma in older patients, with cytogenetic confirmation.


RESULTS
Six cases of lipoblastoma in patients >12 years old were identified. The tumours occurred in four male and two female patients ranging from 14 to 24 years old. Our cases showed the classical histological features of lipoblastoma. Three tumours were composed predominantly of mature adipocytes and the three other cases showed an immature appearance, with a prominent myxoid matrix. Fluorescence in situ hybridization (FISH) demonstrated rearrangements of the PLAG1 region in two cases and polysomy for chromosome 8 in three other cases. None of the tumours had amplification of MDM2 or CDK4.


CONCLUSIONS
Lipoblastoma occurs rarely in young adults and should enter into the differential diagnosis of 'atypical' fatty tumours in adults. Our report underscores the diagnostic value of FISH analysis.
de Saint Aubain Somerhausen
N
N
Department of Pathology, Institut Jules Bordet, Brussels, Belgium. nicolas.desaintaubain@skynet.be
Coindre
J M
JM
Debiec-Rychter
M
M
Delplace
J
J
Sciot
R
R
D017667:Adipocytes / Q000473:pathology; D000293:Adolescent; D000328:Adult; D002869:Chromosome Aberrations; D004273:DNA, Neoplasm / Q000032:analysis*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008067:Lipoma / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D008297:Male; D009364:Neoplasm Recurrence, Local; D012983:Soft Tissue Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000601:surgery
D004273:DNA, Neoplasm