title: Muir-Torre syndrome-associated pleomorphic liposarcoma arising in a previous radiation field.
abstract: Muir-Torre syndrome is a variant of Lynch syndrome, characterised by sebaceous neoplasia and/or keratoacanthomas associated with visceral malignancies. Muir-Torre syndrome is caused by germline mutations of one of the mismatch repair genes, frequently MSH2 and less frequently MLH1 and MSH6. Visceral malignancies associated with Muir-Torre syndrome and Lynch syndrome include colorectal, endometrial and other gastrointestinal, urological and gynaecological malignancies. Small numbers of Lynch syndrome-associated soft tissue sarcomas have been reported, but there are no reported cases of soft tissue sarcomas in Muir-Torre syndrome. In this study, we report a 74-year-old man with known Muir-Torre syndrome with confirmed MSH2 germline mutation, diagnosed with pleomorphic liposarcoma of the right buttock in a previous radiation field. The tumour showed loss of expression of MSH2 and MSH6 on immunohistochemistry. Immunohistochemistry on another pleomorphic liposarcoma in a different patient with no previous history of Muir-Torre syndrome or Lynch syndrome showed no loss of expression of mismatch repair proteins. This is the first report of Muir-Torre syndrome-associated sarcoma and the first case of post-radiation sarcoma in Lynch syndrome.
authors.affiliation: Histopathology Department, Middlemore Hospital, Hospital Road, Otahuhu, Auckland, New Zealand. MasatoY@adhb.govt.nz
authors.forename: Masato
authors.initials: M
authors.lastname: Yozu
authors.forename: Pennie
authors.initials: P
authors.lastname: Symmans
authors.forename: Michael
authors.initials: M
authors.lastname: Dray
authors.forename: Jennifer
authors.initials: J
authors.lastname: Griffin
authors.forename: Catherine
authors.initials: C
authors.lastname: Han
authors.forename: Daniel
authors.initials: D
authors.lastname: Ng
authors.forename: Susan
authors.initials: S
authors.lastname: Parry
authors.forename: Kp
authors.initials: K
authors.lastname: Wong
mesh_terms: D000368:Aged; D004268:DNA-Binding Proteins / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008080:Liposarcoma / Q000235:genetics / Q000473:pathology*; D008297:Male; D055653:Muir-Torre Syndrome / Q000235:genetics / Q000532:radiotherapy*; D051718:MutS Homolog 2 Protein / Q000235:genetics; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000473:pathology*
chemical_list: D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein