MRI features in solitary cerebral Langerhans cell histiocytosis : a case report and review of literature.

BACKGOUND: In this study, we report a case of solitary Langerhans cell histiocytosis (LCH) without skull or systemic lesions including reviewing the initial magnetic resonance (MR) findings of cerebral LCH. CASE DESCRIPTION: A 36-year-old male patient presented with generalized tonic-clonic type seizure. Brain MR imaging showed a 3-cm mass lesion involving the right frontal lobe. It showed isointensity on T1-weighted images and hyperintensity on T2-weighted images. After gadolinium enhancement, the mass showed heterogeneous enhancement with perilesional edema and additional adjacent leptomeningeal enhancement. Special MR techniques focused on the enhanced lesion showed increased cerebral blood volume on perfusion images, no diffusion restriction on diffusion-weighted images, and a necrotic spectrum on MR spectroscopy. At surgery, we found a yellow mass and yellow tissue debris in the sulci adjacent to the mass and removed them. The final histopathologic diagnosis was LCH in the frontal lobe. The patient underwent scheduled adjuvant chemotherapy with cytarabine for 6 months and has been regularly followed up without any neurologic problem for 3 years. CONCLUSIONS: In conclusion, additional sulcal enhancement around the mass lesion might be a clue MR imaging feature of intracerebral LCH, and special MR imaging techniques such as perfusion imaging, diffusion-weighted imaging, and MR spectroscopy could be helpful in differential diagnosis.