title: Recurrent high-grade leiomyosarcoma with heterologous osteosarcomatous differentiation.
abstract: Leiomyosarcomas (LM) of the soft tissue comprise approximately 5-10% of all soft tissue sarcomas. Besides the classic LM, several distinctly uncommon features of the cellular and growth patterns of LM have been described. The term "dedifferentiated LM" has rarely been used in the literature to describe soft tissue LM containing areas of undifferentiated, pleomorphic appearance or detectable heterologous differentiation. We report on a case of high-grade LM with almost entire transition to an osteosarcoma, which was classified as recurrent high-grade LM with heterologous osteosarcomatous differentiation. The identification of areas with osteosarcomatous dedifferentiation in soft tissue sarcomas can be of clinical importance because of a possible change in oncologic treatment strategies.
authors.affiliation: Institute of Pathology, University Hospital of Essen, University Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany. florian.grabellus@medizin.uni-essen.de
authors.forename: Florian
authors.initials: F
authors.lastname: Grabellus
authors.forename: Sien-Yi
authors.initials: SY
authors.lastname: Sheu
authors.forename: Boris
authors.initials: B
authors.lastname: Schmidt
authors.forename: Michael
authors.initials: M
authors.lastname: Flasshove
authors.forename: Cornelius
authors.initials: C
authors.lastname: Kuhnen
authors.forename: Steffen
authors.initials: S
authors.lastname: Ruchholtz
authors.forename: Georg
authors.initials: G
authors.lastname: Taeger
authors.forename: Kurt Werner
authors.initials: KW
authors.lastname: Schmid
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000378:metabolism / Q000473:pathology*; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000378:metabolism / Q000473:pathology*