title: Cerebral tumor or pseudotumor?
abstract: Pseudotumoral lesions are uncommon but important to identity lesions. They can occur during inflammatory diseases (systemic diseases, vasculitis, demyelinating diseases), infectious, and vascular diseases. Also, in a patient with a treated tumor, pseudo-progression and radionecrosis must be differentiated from the tumoral development. Diagnosis can be difficult on an MRI scan, but some MRI aspects in conventional sequences, diffusion, perfusion and spectroscopy can suggest the pseudotumoral origin of a lesion. Imaging must be interpreted according to the context, the clinic and the biology. The presence of associated intracranial lesions can orientate towards a systemic or infectious disease. A T2 hyposignal lesion suggests granulomatosis or histiocytosis, especially if a meningeal or hypothalamic-pituitary involvement is associated. Non-tumoral lesions are generally not hyperperfused. In the absence of a definitive diagnosis, the evolution of these lesions, whether under treatment or spontaneous, is fundamental.
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France. Electronic address: del.leclercq@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Leclercq
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Trunet
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Bertrand
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Galanaud
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Lehéricy
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Dormont
authors.affiliation: Neuroradiology Department, Pitié-Salpêtrière Hospital, 47-83, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Drier
mesh_terms: D001921:Brain / Q000473:pathology; D001927:Brain Diseases / Q000175:diagnosis* / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D003937:Diagnosis, Differential; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011379:Prognosis; D012680:Sensitivity and Specificity
keywords: Behçet; Brain; Histiocytosis; Sarcoidosis; Tumour