title: Rhabdomyosarcoma with pseudolipoblasts arising in ovarian carcinosarcoma: a distinctive postchemotherapy morphologic variant mimicking pleomorphic liposarcoma.
abstract: We describe a case of ovarian carcinosarcoma occurring in a 60-year-old female. The neoplasm was excised after neoadjuvant chemotherapy and contained a predominant heterologous pleomorphic rhabdomyosarcomatous component in which there were numerous multivacuolated rhabdomyoblasts that strongly mimicked lipoblasts. The clear cell variant of rhabdomyosarcoma is rarely documented, but this case shows a highly unusual finding in which the rhabdomyoblasts show the prominent multivacuolation with nuclear indentation characteristic of and indistinguishable from pleomorphic lipoblasts. This appears to represent a posttreatment phenomenon. As this finding might conceivably occur in other rhabdomyosarcomas after chemotherapy, we highlight the potential for diagnostic confusion with pleomorphic liposarcoma, which is usually diagnosed by morphology so that immunohistochemistry for muscle markers might not be performed.
authors.affiliation: Sarcoma Unit, Royal Marsden Hospital, London SW3 6JJ, UK ; Department of Histopathology, The Royal Marsden NHS Foundation Trust, 203 Fulham Road, London SW3 6JJ, UK.
authors.forename: Khin
authors.initials: K
authors.lastname: Thway
authors.affiliation: Department of Histopathology, The Royal Marsden NHS Foundation Trust, 203 Fulham Road, London SW3 6JJ, UK ; Gynaecology Unit, Royal Marsden Hospital, London SW3 6JJ, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: Hazell
authors.affiliation: Gynaecology Unit, Royal Marsden Hospital, London SW3 6JJ, UK.
authors.forename: Susana
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Sarcoma Unit, Royal Marsden Hospital, London SW3 6JJ, UK ; Department of Histopathology, The Royal Marsden NHS Foundation Trust, 203 Fulham Road, London SW3 6JJ, UK.
authors.forename: Cyril
authors.initials: C
authors.lastname: Fisher