title: A rare case of malignant pediatric ectomesenchymoma arising from the falx cerebri.
abstract: Malignant ectomesenchymoma is a rare tumor arising from mature ganglion cells with immature myogenous elements, with only 4 pediatric intracranial cases having been previously reported. The authors report a rare case of intracranial malignant ectomesenchymoma originating from the falx cerebri in a 10-year-old boy. The patient presented with a 2-week history of headache, nausea, and blurry vision, with mild lateral gaze diplopia. A CT scan revealed a solitary 7.2 × 3.8-cm dural-based mass that extended along the falx. No metastatic disease was identified, and the lesion was grossly resected without complication. Pathological investigation identified single and small groups of cells in a myxoid background, with polygonal or spindle-shaped cells containing eccentric nuclei and prominent nucleoli. Immunohistochemical staining of some cells was positive for smooth-muscle actin, CD99, and vimentin, whereas other cells (often process forming) were positive for S100 protein, synaptophysin, and neurofilament protein. Staining was negative for CD138, CD45, α-fetoprotein, CK AE1/3, glial fibrillary acidic protein, CK7, CK20, CD31, CD34, myoD, and desmin. Normal immunopositivity was seen for INI-1. The Ki 67 immunostaining had < 25% reactivity. The patient was treated with a sarcoma-based chemotherapy regimen and radiation to the craniospinal axis, and was found to be without recurrence or metastatic disease at 20 months.
authors.affiliation: Department of Pathology, Orlando Health, 83 West Columbia Street, Orlando, FL 32806, USA.
authors.forename: Dana L
authors.initials: DL
authors.lastname: Altenburger
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Wagner
authors.forename: Don E
authors.initials: DE
authors.lastname: Eslin
authors.forename: Gary S
authors.initials: GS
authors.lastname: Pearl
authors.forename: Jogi V
authors.initials: JV
authors.lastname: Pattisapu
mesh_terms: D000071443:12E7 Antigen; D000199:Actins / Q000032:analysis; D015703:Antigens, CD / Q000032:analysis; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis*; D015815:Cell Adhesion Molecules / Q000032:analysis; D017024:Chemotherapy, Adjuvant; D002648:Child; D004388:Dura Mater / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D008637:Mesenchymoma / Q000737:chemistry / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D016900:Neurofilament Proteins / Q000032:analysis; D018714:Radiotherapy, Adjuvant; D009418:S100 Proteins / Q000032:analysis; D016708:Synaptophysin / Q000032:analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014746:Vimentin / Q000008:administration & dosage
chemical_list: D000071443:12E7 Antigen; D000199:Actins; D015703:Antigens, CD; D014408:Biomarkers, Tumor; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D016900:Neurofilament Proteins; D009418:S100 Proteins; D016708:Synaptophysin; D014746:Vimentin