Soft Tissues: Lipoma / benign lipomatous tumors

2000-05-01 Nils Mandahl Affiliation

1.Department of Clinical Genetics, University Hospital, Lund, Sweden

Summary

Note

lipomas are benign adipose tissue tumors with many subtypes, constituting one-third of all soft tissue tumors

Classification

Ordinary lipoma: the solitary, ordinary lipomas represent the most common soft tissue tumors, with subcutaneous tumors being much more common than the deep-seated ones
Epidemiology: the incidence of lipomas is about one in 1000 inhabitants per year, but is probably underestimated since many lesions cause few problems; they occur most frequently between 30 and 70 years of age, with a peak incidence between 40 and 60 years
Clinics: solitary lipomas are slow-growing masses, most frequently located in the upper back, neck, shoulder, abdomen, and the proximal portions of the extremities
Evolution: surgery is required primarily when the tumors reach large size and cause cosmetic problems or complications due to their anatomical site; there is no risk of progression to malignancy, and recurrences are rare after shelling-out

Angiolipoma: angiolipomas show characteristic histological features and occur primarily as subcutaneous, painful nodules; multiple lesions are much more common than solitary ones; they are usually smaller than solitary, ordinary lipomas and present at an earlier age, with the dominating site being the forearm; an increased familial incidence has been noted

Spindle cell/ pleomorphic lipoma: the characteristic feature of spindle cell lipoma is the replacement of mature fat by collagen-forming spindle cells; these rare tumors typically occur subcutaneously in the neck and shoulders of men aged 45 to 65 years
pleomorphic lipoma probably represents a highly pleomorphic variant of spindle cell lipoma and show similar clinical features;
both of these types of lesions may be confused with liposarcoma

Lipoblastoma: lipoblastoma is a tumor of the infancy; most tumors occur before three years of age and may occasionally be seen already at birth; the site is primarily the upper and lower extremities; there may be a close resemblance to myxoid liposarcoma

Hibernoma: hibernoma is chiefly a tumor of adults, although in average occurring at lower ages than solitary, ordinary lipomas; the most common sites are the scapular and interscapular regions, mediastinum and upper thorax

Angiomyo-lipoma: angiomyolipoma is a hamartomatous lesion in the kidneys of adult patients, with a preponderance of women

Chondroid lipoma: chondroid lipoma is a rare tumor occurring in the subcutis or muscle of adults; it may be confused with liposarcoma and chondrosarcoma, and shows microscopic features of both lipoma and hibernoma

Cytogenetics

Cytogenetics morphological

Chondroid lipoma: a cytogenetically identical rearrangement, t(11;16)(q13;p13), found in the only two cases reported indicate that this is a recurrent aberration

Article Bibliography

Pubmed ID	Last Year	Title	Authors
10448117	1999	Fusion genes in solid tumors.	Aman P et al
8824803	1996	Genomic characterization of human HMGIC, a member of the accessory transcription factor family found at translocation breakpoints in lipomas.	Ashar HR et al
7606786	1995	Disruption of the architectural factor HMGI-C: DNA-binding AT hook motifs fused in lipomas to distinct transcriptional regulatory domains.	Ashar HR et al
7534115	1995	Translocation t(3;12)(q28;q14) in parosteal lipoma.	Bridge JA et al
9398869	1997	Chromosome analysis in angiomyolipoma.	Dal Cin P et al
1377003	1992	Cytogenetic analysis of renal angiomyolipoma.	Debiec-Rychter M et al
8579124	1996	Correlation between clinicopathological features and karyotype in lipomatous tumors. A report of 178 cases from the Chromosomes and Morphology (CHAMP) Collaborative Study Group.	Fletcher CD et al
7680218	1993	Cytogenetic findings in pediatric adipose tumors: consistent rearrangement of chromosome 8 in lipoblastoma.	Fletcher JA et al
10393837	1999	Hibernomas are characterized by homozygous deletions in the multiple endocrine neoplasia type I region. Metaphase fluorescence in situ hybridization reveals complex rearrangements not detected by conventional cytogenetics.	Gisselsson D et al
9169035	1997	Chromosomal aberration in lipoblastoma: a case with 46,XX,ins(8;6)(q11.2;q13q27).	Kanazawa C et al
8791679	1996	Cytogenetics and molecular genetics of bone and soft tissue tumors.	Mandahl N et al
7515663	1994	Cytogenetic aberrations in 188 benign and borderline adipose tissue tumors.	Mandahl N et al
7798294	1994	A new cytogenetic subgroup in lipomas: loss of chromosome 16 material in spindle cell and pleomorphic lipomas.	Mandahl N et al
8111740	1994	Involvement of 10q22 and 11q13 in hibernoma.	Meloni AM et al
9403060	1997	Identification of new translocation breakpoints at 12q13 in lipomas.	Merscher S et al
8056446	1994	Hibernomas are characterized by rearrangements of chromosome bands 11q13-21.	Mertens F et al
8453640	1993	Chromosome 12 breakpoints are cytogenetically different in benign and malignant lipogenic tumors: localization of breakpoints in lipoma to 12q15 and in myxoid liposarcoma to 12q13.3.	Mrózek K et al
9772907	1998	Translocation (11;14)(q13;q32) and overexpression of cyclin D1 protein in a CD23-positive low-grade B-cell neoplasm.	Nanjangud G et al
8812423	1996	LPP, the preferred fusion partner gene of HMGIC in lipomas, is a novel member of the LIM protein gene family.	Petit MM et al
10329012	1999	LHFP, a novel translocation partner gene of HMGIC in a lipoma, is a member of a new family of LHFP-like genes.	Petit MM et al
9772904	1998	Expression of reciprocal fusion transcripts of the HMGIC and LPP genes in parosteal lipoma.	Petit MM et al
2095704	1990	Cytogenetic analysis of a rare case of pediatric myxolipoma.	Peulve P et al
9598796	1998	The t(3;12)(q27;q14-q15) with underlying HMGIC-LPP fusion is not determining an adipocytic phenotype.	Rogalla P et al
7670494	1995	Recurrent rearrangements in the high mobility group protein gene, HMGI-C, in benign mesenchymal tumours.	Schoenmakers EF et al
9130991	1997	Cytogenetic analysis of subcutaneous angiolipoma: further evidence supporting its difference from ordinary pure lipomas: a report of the CHAMP Study Group.	Sciot R et al
9763652	1998	The cytogenetic and molecular characterization of benign and malignant soft tissue tumors.	Sreekantaiah C et al
9352790	1997	Overrepresentation of 1q21-23 and 12q13-21 in lipoma-like liposarcomas but not in benign lipomas: a comparative genomic hybridization study.	Szymanska J et al
9212729	1997	Expression of HMGI-C and HMGI(Y) in ordinary lipoma and atypical lipomatous tumors: immunohistochemical reactivity correlates with karyotypic alterations.	Tallini G et al
8330272	1993	A case report of fibrolipoma with t(12;16)(q13;q24).	Tayyeb MT et al
9950168	1999	Cytogenetic and cytologic features of chondroid lipoma of soft tissue.	Thomson TA et al
9530339	1998	Comparison of chromosomal patterns with clinical features in 165 lipomas: a report of the CHAMP study group.	Willén H et al

External Links

Citation

Nils Mandahl

Soft Tissues: Lipoma / benign lipomatous tumors

Atlas Genet Cytogenet Oncol Haematol. 2000-05-01

Online version: http://atlasgeneticsoncology.org/solid-tumor/5050/lipomaid5050