Solitary Langerhans cell histiocytosis lesion of the parieto-occipital lobe: a case report and review of the literature.

A 38 year-old woman with a solitary intracerebral Langerhans cell histocytosis (LCH) lesion is presented, in whom, cerebral magnetic resonance imaging (MRI) revealed a non-enhancing mass in the right parieto-occipital lobe. The surgical specimen consisted of a nodular polymorphic infiltrate of mononuclear histiocytic cells, macrophages, eosinophilic granulocytes, lymphocytes and Langerhans giant cells involving leptomeninges, cerebral cortex and white matter. The histiocytes displayed features of Langerhans cells such as CD1a and S-100 immunopositivity, and of reticulum cells such as Ki-M4P and X-12 immunopositivity. This case as well as ten other cases from the literature are reviewed.