Cerebral solitary Langerhans cell histiocytosis: report of two cases and review of the literature.

Cerebral solitary Langerhans cell histiocytosis (LCH) is a very uncommon condition. We describe two new cases: a 30-year-old man with seizures and a tumour in the left frontal lobe, which was composed of a polymorphic infiltrate with a predominance of histiocytes and eosinophils; and a 65-year-old man with headaches and dysarthria, with a left parietal tumour, which showed a diffuse proliferation of histiocytic cells and areas of necrosis. In both cases, the histiocytes were strongly positive for S-100 and CD1a, and Birbeck's granules were demonstrated by electron microscopy in the first case. Both patients underwent a complete excision of their lesions. The second patient received additional postoperative radiotherapy. They were asymptomatic after 26 and 27 months, respectively. It seems that cerebral solitary LCH is a clinicopathological entity with a good outcome. Only 15 cases of this rare process have been previously reported in the English literature [ABSTRACT FROM AUTHOR]