[Mycoplasma pneumoniae meningoencephalitis]. / Méningoencéphalite à Mycoplasma pneumoniae.

BACKGROUND: Severe central nervous system diseases, such as encephalitis, have been reported in association with Mycoplasma pneumoniae infections. CASE REPORT: After an ENT infection, a 9-year-old boy with Down's syndrome developed encephalitis revealed by an acute alteration in consciousness. Head computed tomography showed, after 2 weeks, an infiltration in the basal ganglia region. The diagnosis of Mycoplasma pneumoniae encephalitis was made; recovery was complete in a few weeks. CONCLUSION: Mycoplasma pneumoniae infection should be considered in all cases of acute encephalopathy; yet the pathogenesis of the disorder is unknown and the treatment uncertain.

[Sinus histiocytosis (Destombes-Rosai-Dorfman disease) revealed by extranodal spinal involvement]. / Histiocytose sinusale (maladie de Destombes-Rosai-Dorfman) révélée par une atteinte extraganglionnaire rachidienne.

BACKGROUND: Sinus histiocytosis with massive cervical lymphadenopathy (Rosai-Dorfman disease) is a non-neoplastic lymphoproliferative disorder. Extranodal involvement, especially of the nervous system, is unusual. We report a case revealed by neurological symptoms. CASE REPORT: A 10-year-old girl presented with paraparesis due to a dural extramedullary mass on magnetic resonance imaging. Massive cervical lymphadenopathy appeared secondarily. Radiological investigations showed mediastinal, paranasal sinus and lower eyelid involvement. The diagnosis of Rosai-Dorfman disease was established histologically and by immunohistochemical studies of nodal lesions by the demonstration of characteristic sinus histiocytosis with sheets of S-100 protein and CD-68 positive large histiocytes displaying lymphocyte phagocytosis. A dramatic response occurred with complete resolution of all clinical findings after treatment with corticosteroids and etoposide, although neurological lesions were unchanged on magnetic resonance imaging. CONCLUSION: Despite its rarity, this case underlines the unknown pathogenesis of this disease (immune dysfunction?) and the difficulties of treatment (choice of chemotherapeutic agents, duration).

[Undifferentiated soft tissue tumor with rhabdoid phenotype (extra-renal rhabdoid tumor). Report of a congenital case associated with medulloblastoma in a brother]. / Tumeur indifférenciée des tissus mous avec phénotype rhabdoïde (tumeur rhabdoïde extra-rénale). A propos d'un cas congénital associé à un médulloblastome dans la fratrie.

We report a case of congenital cervical rhabdoid tumor with association of a medulloblastoma in a brother. The immunohistochemical features of this tumor are compatible with a neuroectodermal differentiation (MIC 2+, Leu 7+). Extrarenal rhabdoid tumors share a common morphology but do not represent a single entity with only one histogenesis. Most of them are now considered to be of neuroectodermal origin. In our case, the association with a medulloblastoma in a brother seems to confirm this concept.