[An unusual form of neurosarcoidosis isolated in association with a tumoral lesion, chronic meningitis, hydrocephalus and hypothalamo-hypophyseal involvement]

Abstract

A 30-year-old woman developed progressive left sided hemiparesis with intracranial hypertension signs. CT scan and MRI showed a large temporo parietal cystic mass with marked surrounding edema. Surgical excision was performed, and histological analysis revealed an inflammatory granuloma. No disease elsewhere was found and all classical causes of granulomas such as tuberculosis, toxoplasma, fungus infections, inflammatory diseases, lymphomas and cancers were excluded. No treatment was administered and she remained neurologically stable for two years. Afterwards, she developed chronic meningo-encephalitis, hypothalamic-pituitary dysfunction and hydrocephalus requiring decompression. Sarcoidosis was suspected, a steroid therapy was initiated, she gradually improved and a ventricular biopsy confirmed this diagnosis. Nervous system lesions complicate the course of sarcoidosis in 5 to 15% of patients and most commonly involve the cranial and peripheral nerves. CNS involvement is typically meningeal with a predilection for the hypothalamic region. Intracranial mass lesions are rare and their occurrence in the absence of disease elsewhere is still more unusual. Three presentations have been described: an isolated intra parenchymatous mass, multiples nodules, and subdural plaques, that can be mistaken for meningiomas, gliomas or metastases. When systemic manifestations of sarcoidosis are absent, the diagnosis is difficult, and Gd-enhanced MRI is now considered the diagnostic method of choice. However brain biopsy is sometimes necessary. Corticosteroids are the mainstay of therapy. Immunosuppressive agents are also used and brain irradiation has been tried in some refractory cases. Surgical approach may be indicated to establish tissue diagnosis, to perform decompression and to remove brain tumors.