%0 Journal Article
%T Rhabdomyosarcoma with Pseudolipoblasts Arising in Ovarian Carcinosarcoma: A Distinctive Postchemotherapy Morphologic Variant Mimicking Pleomorphic Liposarcoma
%A Khin Thway
%A Steve Hazell
%A Susana Banerjee
%A Cyril Fisher
%J Case Reports in Pathology
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/238545
%X 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. 1. Introduction Carcinosarcomas of the gynaecological tract (malignant mixed Mullerian tumors; MMMT) are neoplasms composed of malignant epithelial and mesenchymal components that most frequently arise in the uterus but also occur at a variety of other sites in the genital tract. Heterologous mesenchymal differentiation can occur toward a variety of lineages, including to rhabdomyosarcoma, chondrosarcoma and osteosarcoma, and more rarely liposarcoma. Here, we present a case of ovarian carcinosarcoma with heterologous pleomorphic rhabdomyosarcomatous differentiation, which was excised after neoadjuvant chemotherapy and showed a morphologically striking pattern of lipoblast-like rhabdomyoblasts. This is in keeping with an unusual posttreatment degenerative change, and we highlight its potential for diagnostic error as pleomorphic liposarcoma. 2. Case Report A 60-year-old female presented acutely with fever, abdominal pain, and a palpable mass after several months¡¯ history of mild abdominal discomfort and bloating. She was previously fit and healthy, without significant past medical or family history. Computed tomography (CT) and magnetic resonance imaging (MRI) scans showed complex solid cystic bilateral adnexal masses measuring up to 11£¿cm and consistent with malignant ovarian tumor, with bulky pelvic and paraaortic lymphadenopathy. No other disease foci were noted. CA125 was raised at over 2000£¿IU/mL, but CA153, CA19-9, CEA, AFP, and BHCG were all within normal range. She was treated with intravenous antibiotics, and the pelvic lesion was biopsied. Needle core biopsy showed high grade serous adenocarcinoma, in keeping with either primary peritoneal,
%U http://www.hindawi.com/journals/cripa/2014/238545/