title: Primary central nervous system histiocytic sarcoma with relapse to mediastinum: a case report and review of the literature.
abstract: Histiocytic sarcoma is a rare, malignant neoplasm of the lymphohematopoietic system that usually occurs in the skin, lymph node, and intestinal tract. Here we describe a unique case of primary central nervous system histiocytic sarcoma that initially showed an indolent clinical course following local resection and radiotherapy. However, relapse of disease within the mediastinum was noted 3 1/2 years later. Biopsies of the initial brain lesion and subsequent mediastinal recurrence each revealed an identical, diffuse proliferation of histiocytes with expression of CD45, CD68, and CD163 but not pan-cytokeratin, epithelial membrane antigen, CD3, CD15, CD20, CD30, CD43, CD79a, CD138, myeloperoxidase, ALK-1, PAX-5, CAM 5.2, S100, CD1a, or glial fibrillary acidic protein. In the literature, central nervous system histiocytic sarcoma portends a poor prognosis with median survival of 4.5 months. To our knowledge, this case represents the first case of "low-grade" primary central nervous system histiocytic sarcoma with relatively indolent clinical course. A thorough discussion of the differential diagnosis of histiocytic sarcoma and a review of primary central nervous system histiocytic sarcoma are also presented.
authors.affiliation: Department of Pathology, The Methodist Hospital, Weill Medical College of Cornell University, Houston, TX 77030, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Cao
authors.forename: Camellia
authors.initials: C
authors.lastname: Eshoa
authors.forename: Christopher
authors.initials: C
authors.lastname: Schultz
authors.forename: Jennifer
authors.initials: J
authors.lastname: Black
authors.forename: Youli
authors.initials: Y
authors.lastname: Zu
authors.forename: Chung-Che
authors.initials: CC
authors.lastname: Chang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D003937:Diagnosis, Differential; D005260:Female; D015620:Histiocytic Disorders, Malignant / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007150:Immunohistochemistry; D008479:Mediastinal Neoplasms / Q000378:metabolism / Q000556:secondary*; D008875:Middle Aged; D012509:Sarcoma / Q000378:metabolism / Q000556:secondary* / Q000628:therapy
chemical_list: D014408:Biomarkers, Tumor