title: Rare primary CNS anaplastic large cell lymphoma in an immunocompetent adult: a clinical-pathologic case report and review case of the literature.
abstract: OBJECTIVE
  Isolated anaplastic large cell lymphoma (ALCL) presenting in the primary central nervous system is distinctly uncommon. The authors describe a case that clinically and radiographically simulated a primary glial neoplasm.
  
  
  METHODS
  A 39-year-old immunocompetent male presented with seizures and a rapidly enlarging right occipital/parietal lesion. Magnetic resonance images demonstrated a right occipitoparietal lesion, hypodense on T1WI, with patchy contrast enhancement with gadolinium and significant white matter edema pattern on T2WI along with mass effect and midline shift.
  
  
  METHODS
  The patient underwent a frameless stereotactic assisted needle biopsy. There appeared to be a clear demarcation between white matter and tumor with no obvious necrosis. Biopsy showed a proliferation of single cells and poorly cohesive groups of cells with large, pleomorphic nuclei, many containing prominent nucleoli, and a moderate amount of cytoplasm. Immunohistochemical staining revealed CD-30 and ALK-positivity typical of ALCL, a rare form of T-cell lymphoma. An extensive workup revealed neither systemic disease nor evidence of immunocompromise.
  
  
  CONCLUSIONS
  Reported in less than 20 patients, primary ALCL in an immunocompetent patient is rarely found intracranially; however, its ability to mimic glial neoplasms as well as other pathologies underlines its importance.
authors.affiliation: Department of Neurosurgery, National Capitol Consortium, Walter Reed Army Medical Center, Washington DC, USA.
authors.forename: P B
authors.initials: PB
authors.lastname: Cooper
authors.forename: A
authors.initials: A
authors.lastname: Auerbach
authors.forename: N S
authors.initials: NS
authors.lastname: Aguilera
authors.forename: C
authors.initials: C
authors.lastname: Adair
authors.forename: L
authors.initials: L
authors.lastname: Moores
authors.forename: D
authors.initials: D
authors.lastname: Geyer
authors.forename: E J
authors.initials: EJ
authors.lastname: Rushing
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D005910:Glioma / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D016403:Lymphoma, Large B-Cell, Diffuse / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D011878:Radiotherapy; D012640:Seizures / Q000209:etiology
chemical_list: D014408:Biomarkers, Tumor