title: Sellar and parasellar intravascular lymphoma mimicking pituitary apoplexy.
abstract: BACKGROUND
  Intravascular lymphoma (IVL) is a rare subtype of large-cell non-Hodgkin lymphoma, characterized by proliferation of lymphoma cells within the lumina of small vessels. There are no previously reported cases of IVL involving the pituitary gland presenting with neuro-ophthalmic findings.
  
  
  METHODS
  A 68-year-old female presented with headache, right third nerve palsy, and Horner syndrome. MRI showed a 1.4-cm sellar mass consistent with a pituitary macroadenoma. Two weeks later, despite treatment with dexamethasone, the patient developed complete bilateral ophthalmoplegia and ptosis. Repeat MRI showed invasion of the clivus and cavernous sinuses, and a transsphenoidal pituitary biopsy was undertaken.
  
  
  RESULTS
  The preliminary histopathology was consistent with bland pituitary apoplexy, but subsequent examination of an incidentally biopsied nasal polyp revealed endovascular malignant lymphoid cells that, on further scrutiny, were also present in the pituitary tissue. The diagnosis of IVL was confirmed, and the patient had an excellent clinical and radiological response to cyclophosphamide, doxorubicin, vincristine, prednisolone, and rituximab (CHOP-R) chemotherapy.
  
  
  CONCLUSIONS
  IVL may involve the pituitary gland, causing sellar mass effect, cavernous sinus infiltration, and pituitary ischemia, mimicking pituitary apoplexy with neuro-ophthalmic features. It can be effectively treated with CHOP-R chemotherapy.
authors.affiliation: Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Rizek
authors.forename: Maayan
authors.initials: M
authors.lastname: Seitelbach
authors.forename: Murad
authors.initials: M
authors.lastname: Alturkustani
authors.forename: Andrew
authors.initials: A
authors.lastname: Leung
authors.forename: J Alexander
authors.initials: JA
authors.lastname: Fraser
mesh_terms: D000368:Aged; D020226:Cavernous Sinus Thrombosis / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D003937:Diagnosis, Differential; D005260:Female; D006393:Hemangiopericytoma / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D009886:Ophthalmoplegia / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D010911:Pituitary Neoplasms / Q000556:secondary*; D019043:Vascular Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology