Clinicopathological characteristics of atypical spindle cell lipomatous tumours:report of eight cases
Purpose To explore the clinicopathological characteristics of atypical spindle cell lipomatous tumour(ASLT).Methods The clinical pathology,immunopheno-type,and molecular characteristics of 8 ASLTs diagnosed and treated in Fujian Cancer Hospital from 2020 to 2023 were col-lected.The histological morphology,immunophenotype and mo-lecular characteristics of 8 ASLTs were evaluated by HE stai-ning,immunohistochemistry and FISH.Clinicopathological fea-tures of 8 ASLTs were analyzed with literature review.Results Mixed distribution of spindle cells and adipocytes in different proportions was seen in all 8 cases,with no or mild cell atypia and no necrosis.Immunophenotypically,8 ASLTs were CD34 and S-100 positive to varying degrees,RB was negative,MDM2 and CDK4 were negative or focus positive,and Ki67 prolifera-tion index was low.FISH showed MDM2 amplification was nega-tive in 6 cases.Conclusion ASLT is a newly named benign adipose-derived tumor subtype with unique morphology,immu-nophenotype,and molecular characteristics.It has a good prog-nosis.Correct diagnosis can avoid clinical over-treatment.