[MRI aspect and course of supra-tentorial sarcoidosic lesions]

Central nervous system lesions resulting from sarcoidosis occur in 5% of cases, but supratentorial mass lesions are uncommon. We report 3 cases of intracranial pseudo-tumoral lesions, due to sarcoidosis: 1 woman and 2 men. Clinical features included left facial myoclonus, headache and vertigo, right hemiparesis and unique general seizure. Sarcoidosis was diagnosed upon conjonctival biopsy in the first case, infiltrative lesions of the lungs and mediastinal lymph nodes in the second case, and intracerebral lesion plus lymph nodes biopsies in the last case. In the first case, CT scan and MRI images showed diffuse subcortical high signal, suggesting pachymeningitis with vasogenic oedema. In the second case, GT scan and MRI revealed numerous small granuloma in the left rolandic area, and one in the striatum. In the third case, CT scan showed an enlargement of the left temporal horn, due to an enhanced left periventricular lesion. MRI with gadolinium showed that the lesion encircled the ventricle horn. In all cases, clinical and radiological improvement was obtained after corticoid therapy.