title: "Low-Fat" Pseudoangiomatous Spindle Cell Lipoma: A Rare Variant With Loss of 13q14 Region.
abstract: Spindle cell and pleomorphic lipoma constitute a spectrum of lipomatous lesions with characteristic clinical, morphologic, immunohistochemical, and molecular features. Multiple variants have been previously described including vascular, fibrous, plexiform, and those with significantly less fat termed "low-fat" and "fat-free" by Folpe. Cytogenetically, spindle cell lipomas frequently display monoallelic loss of 13q14 region, an abnormality also found in cellular angiofibroma and mammary-type myofibroblastoma. Pseudoangiomatous spindle cell lipoma, originally described by Fletcher et al in 1994, is a rare variant within the spindle cell/pleomorphic lipoma spectrum, with less than 20 published cases. It consists of an admixture of spindle cells, "ropey" collagen, variable amounts of mature fat, and irregular, branching slit-like vascular spaces. The authors present a case of a 1-cm subcutaneous lesion excised from the neck of a 70-year-old man with classic histologic and immunohistochemical features of "low-fat" pseudoangiomatous spindle cell lipoma. Fluorescence in situ hybridization demonstrated a loss of 13q14 region, a characteristic presumed cytogenetic finding of spindle cell lipoma, which has been previously unconfirmed in this variant.
authors.affiliation: Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Forcucci
authors.forename: Jessica Z
authors.initials: JZ
authors.lastname: Sugianto
authors.forename: Daynna J
authors.initials: DJ
authors.lastname: Wolff
authors.forename: John C
authors.initials: JC
authors.lastname: Maize
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Ralston
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D003937:Diagnosis, Differential; D006391:Hemangioma / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008067:Lipoma / Q000235:genetics* / Q000473:pathology*; D008297:Male; D009333:Neck / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor
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