Cranial Nerves Paralysis Revealing Two Cases of Histiocytic Sarcoma.

Pathological, immuno-chemical and cytogenetic studies have allowed in the two last decades to distinguished real histiocytic sarcoma (HS) from hemophagocytic activation syndrome secondary to lymphoma, Langerhans histiocytosis, benign histiocytic proliferation or dendritic cells tumor. Strict immunophenotypic criteria have been defined by the International Lymphoma Study Group (ILSG) in 2002. Published cases are rare as most cases have been reclassified into lymphoma. Clinical presentation is bad known. We report two cases with initial neurological involvement. Case 1: A 32-year-old black patient was admitted in hospital in May 2002 for rapidly progressive blurred vision of the right eye, bilateral deafness and marked gait disturbance. Physical examination demonstrated hepatosplenomegaly, ataxia, bilateral deafness and loss of visual acuity mainly in the right eye. MR imaging of the brain demonstrated white matter abnormalities. Cerebrospinal fluid (CSF) study showed mild protein level (0.43g/l), low glucose level and 16/mm3 histiocytic cells. Bone marrow biopsy, liver biopsies, bone scan, thoracic CT scan were all normal. A diagnostic splenectomy was performed. Pathological study was consistent with HS. Despite high dose systemic chemotherapy containing cytosine-arabinoside, methotrexate, methylprednisolone and intrathecal therapy, he developed kidneys’ tumoral infiltration. After two courses of cladribine the patient died with intra cranial hypertension symptoms. Bone marrow smears demonstrated tumoral infiltration. Case 2: A 63-year-old white female patient presented in november 2002 a one month history of paresthesias in the left trigeminal nerve. CSF study demonstrated high protein level (0.5 g/l), normal glucose, increased cells (21/mm3). Brain MR imaging showed nodular lesions of both trigeminal nerves and protuberance. After 5 days course of intravenous high dose methylprednisolone her state worsened. A left trigeminal nerve chirurgical biopsy was performed. Histologic study diagnosed HS. Abdominal and thoracic CT scan and bone marrow biopsy were normal. Despite high dose chemotherapy including ifosfamide, cytosine-arabinoside and methotrexate, she died with progressive neurological symptoms. Pathological study performed on spleen (case1) and on trigeminal nerve (case2) demonstrated diffuse infiltration by non-cohesive large cells with abundant eosinophilic cytoplasm. Hemophagocytosis in tumoral cells were noted in the 2 cases. Immunophenotyping asserted HS (Table1). Cytogenetic study performed in bone marrow of patient 1 demonstrated clonal complexe karyotype. We report the first 2 cases of HS with initial cranial nerve involvement and complete immunophenotypic study. Only 5 other cases with neurological involvement, either cerebral or spinal cord mass are described to date. The two cases fulfil the WHO and ILSG criteria for HS and immunostaining for CD163 (hemoglobin scavenger receptor), the most histiocyte specific marker, is strongly positive in the two cases. Clonality is demonstrated in case1.