title: Dedifferentiated liposarcoma of the pyriform sinus: report of a case and review of the literature.
abstract: Laryngeal and hypopharyngeal liposarcomas are extraordinarily infrequent tumors. To the best of our knowledge there are fewer than 40 well-documented cases reported to date. Almost all of them are well-differentiated liposarcomas, with only 2 laryngeal-hypopharyngeal dedifferentiated liposarcomas. Dedifferentiated liposarcoma is defined as a well-differentiated liposarcoma with areas of high-grade spindle cell nonlipogenic sarcoma. The well-differentiated areas may be of a lipoma-like, sclerosing, or mixed type, and the dedifferentiated areas most frequently are of malignant fibrous hystiocytoma-like type. Despite its commonly pleomorphic histology, dedifferentiated liposarcoma does not behave as aggressively as most pleomorphic sarcomas of adulthood; however, it has the capacity to metastasize, in contrast to its well-differentiated counterpart. We present a case of dedifferentiated liposarcoma arising in the pyriform sinus, an event only twice reported previously in the literature.
authors.affiliation: Pathology Department, University Hospital Doce de Octubre, Ctra. De Andalucía Km. 5,400, Madrid 28041, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Lois
authors.forename: Carolina
authors.initials: C
authors.lastname: Ibarrola
authors.forename: Claudio
authors.initials: C
authors.lastname: Ballestín
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Martánez-Tello
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007825:Laryngectomy; D008080:Liposarcoma / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D010039:Otorhinolaryngologic Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor