Neuropathologie

Cas 1100842

Liens et agrandissements sur : images et texte en bleu. Links - Zoom: pictures and highlighted text.
 

Patiente de 62 ans admise pour
biopsie stéréotaxique d’une masse
cérébrale. Pas d'antécédents personnels ou familiaux.

Se plaint depuis 1mois de nausées
et depuis 15 jours, s'installe une altération de l'état général, de faux vertige, d'une dysarthrie et d'une faiblesse du membre supérieur droit. A l'examen clinique il existe une hypoesthésie de l’hémiface gauche.

Le bilan sanguin est sans particularité.

 

62 yo female, sent for stereotaxic biopsy of a brain mass. No personnal or familial particular history.

She complained of nausea for the last month, and vertigo the last two weeks, with general weakness, fatigue, dysarthria, and weakness of right upper limb. Physical examination, demonstrates an hypoesthesia of the left part of the face.

Blood tests were unremarkable.

 
  Imagerie   MRI  
     
     
 

Biopsie stéréotaxique : Ecrasis

 

Stereotaxic biopsy: Crush smear

 
     
     
  Biopsie stéréotaxique   Stereotaxic biopsy  
     
     
         
     
  GFAP   Neurofilaments  
     
  CD68   CD68  
     
    Luxol fast blue  
         
 

Diagnostic proposé

 

 

 

 

 

 

 

Pseudo-tumeur démyélinisante

 

Proposed diagnosis

 

 

 

 

 

 

 

Demyelinating pseudo-tumour

 
  Arguments      
 

 

Ann Diagn Pathol. 2002 Oct;6(5):265-71.

Demyelinating pseudotumor.

Erana-Rojas IE, Barboza-Quintana A, Ayala AG, Fuller GN.

Department of Pathology, Hospital San Jose-Tec de Monterrey, Monterrey, Nuevo Leon, Mexico.

Abstract

Demyelinating disease presenting as a solitary contrast-enhancing mass poses a diagnostic challenge for both radiologists and surgical pathologists. We report the cases of two female patients, aged 23 and 37 years, who exhibited the clinical and radiologic features of a space-occupying mass strongly suggestive of neoplasia. In both patients, magnetic resonance imaging showed a ring-enhancing parietal lesion. Intraoperative frozen sections in both patients displayed histologic features strongly suggestive of a glial neoplasm, including marked hypercellularity, a prominent astrocytic component, and easily identifiable mitotic figures. However, permanent sections showed additional and helpful histologic findings that included Creutzfeldt astrocytes and granular mitoses. Subsequent immunostaining showed that the hypercellularity was principally caused by macrophage infiltration (HAM-56 and CD68) and an associated reactive astrocytosis (glial fibrillary acidic protein). Additional confirmatory tests included special stains for myelin (Luxol-fast-blue), which demonstrated focal, sharply marginated loss of myelin, and for axons (silver stain for axons and neurofilament protein immunohistochemistry), which showed relative preservation of axons in areas of myelin loss. Together, the special stains confirmed the demyelinating nature of the lesions. The keys to avoiding misdiagnosing a demyelinating pseudotumor as a diffuse glioma include a general awareness of this potential pitfall, including the radiologic appearance of demyelinating pseudotumors as contrast-enhancing solitary masses that mimic tumor; knowledge of the characteristic histologic features, including Creutzfeldt astrocytes and granular mitoses; and a high index of suspicion for macrophage infiltration combined with a willingness to use appropriate confirmatory immunohistochemical studies in suspicious or uncertain cases. This approach will minimize the chance of misdiagnosis and subsequent use of inappropriate and deleterious therapies.

Présentation du cas par l'interne du Service de Pathologie