title: Hemorrhagic intramedullary solitary fibrous tumor of the conus medullaris: case report.
abstract: The differential diagnosis of spinal tumors is guided by anatomical location and imaging characteristics. Diagnosis of rare tumors is made challenging by abnormal features. The authors present the case of a 47-year-old woman who presented with progressive subacute right lower-extremity weakness and numbness of the right thigh. Physical examination further revealed an extensor response to plantar reflex on the right and hyporeflexia of the right Achilles and patellar reflexes. Magnetic resonance imaging of the lumbar spine demonstrated an 8-mm intramedullary exophytic nodule protruding into a hematoma within the conus medullaris. Spinal angiography was performed to rule out an arteriovenous malformation, and resection with hematoma evacuation was completed. Pathological examination of the resected mass demonstrated a spindle cell neoplasm with dense bundles of collagen. Special immunostaining was performed and a diagnosis of solitary fibrous tumor (SFT) was made. SFTs are mesenchymally derived pleural neoplasms, which rarely present at other locations of the body, but have been increasingly described to occur as primary neoplasms of the spine and CNS. The authors believe that this case is unique in its rare location at the level of the conus, and also that this is the first report of a hemorrhagic SFT in the spine. Therefore, with this report the authors add to the literature the fact that this variant of an increasingly understood but heterogeneous tumor can occur, and therefore should be considered in the differential of clinically similar tumors.
authors.affiliation: Division of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona;
authors.forename: Corey T
authors.initials: CT
authors.lastname: Walker
authors.affiliation: Division of Neurosurgery, University of California-San Diego; and.
authors.forename: Chiazo S
authors.initials: CS
authors.lastname: Amene
authors.affiliation: Division of Neurosurgery, University of California-San Diego; and.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Pannell
authors.affiliation: Division of Neurosurgery, University of California-San Diego; and.
authors.forename: David R
authors.initials: DR
authors.lastname: Santiago-Dieppa
authors.affiliation: Division of Neurosurgery, University of California-San Diego; and.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Rennert
authors.affiliation: Department of Pathology, University of California-San Diego, California.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Hansen
authors.affiliation: Division of Neurosurgery, University of California-San Diego; and.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Khalessi
mesh_terms: D001706:Biopsy; D003937:Diagnosis, Differential; D005260:Female; D006406:Hematoma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D054364:Solitary Fibrous Tumors / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D013116:Spinal Cord / Q000473:pathology*; D013120:Spinal Cord Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*
keywords: EMA = epithelial membrane antigen; GFAP = glial fibrillary acidic protein; SFT = solitary fibrous tumor; SMA = smooth muscle actin; conus medullaris; hemorrhage; intramedullary; lumbar; solitary fibrous tumor; spine