title: Low-grade endometrial stromal sarcoma with intracardiac extension. Evolution of extensive smooth muscle differentiation and usefulness of immunohistochemistry for its recognition and distinction from intravenous leiomyomatosis.
abstract: This case, a rare example of low-grade endometrial stroma sarcoma with extensive smooth muscle differentiation which extended to the inferior vena cava and cardiac chambers closely resembling intravenous leiomyomatosis grossly and microscopically, illustrates the importance of extensive sectioning and the usefulness of immunohistochemistry. Although spindle cell components arranged in interlacing bundles consistent with smooth muscle differentiation were recognizable in the primary tumor (on retrospective review), extensive smooth muscle differentiation in the recurrent tumors masked prototypical morphologic features of stromal sarcoma and only small neoplastic stromal components were preserved in limited areas, leading to initial failure to distinguish the lesion from intravenous leiomyomatosis. The immunophenotyping disclosed two distinct cell populations in the tumor: i.e. vimentin-positive and smooth muscle marker negative stromal cells, and vimentin-negative spindle-shaped desmin-positive smooth muscle cells. Our observation suggests that the predominance of a smooth muscle component in such a tumor can be misleading and does not always warrant a diagnosis of intravenous leiomyomatosis, nor does it predict a benign clinical course. This case also provides an insight into the relationship of the endometrial stroma and myometrium, and their cell of origin and the histogenesis of endometrial stromal sarcoma.
authors.affiliation: Department of Pathology, Kawasaki Medical School Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Mikami
authors.forename: R I
authors.initials: RI
authors.lastname: Demopoulos
authors.forename: F
authors.initials: F
authors.lastname: Boctor
authors.forename: E F
authors.initials: EF
authors.lastname: Febre
authors.forename: M
authors.initials: M
authors.lastname: Harris
authors.forename: I
authors.initials: I
authors.lastname: Kronzen
authors.forename: J V
authors.initials: JV
authors.lastname: Scholes
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D002454:Cell Differentiation; D003893:Desmin / Q000378:metabolism; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D016889:Endometrial Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D005260:Female; D006338:Heart Neoplasms / Q000556:secondary* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D018231:Leiomyomatosis / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D018203:Sarcoma, Endometrial Stromal / Q000378:metabolism / Q000556:secondary* / Q000648:ultrastructure; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D003893:Desmin; D014746:Vimentin