A case of lymphomatoid granulomatosis/angiocentric immunoproliferative lesion with long clinical course and diffuse brain involvement.

Lymphomatoid granulomatosis (LYG)/angiocentric immunoproliferative lesions (AIL) consist of angiocentric and angiodestructive lymphoreticular proliferation predominantly involving the lungs and other extranodal sites, such as the central nervous system (CNS). This clinical entity is considered as a B cell process related to Epstein-Barr virus (EBV) infection and EBV positive diffuse large B-cell lymphoma. The CNS is involved in 20% of cases of LYG, but initial involvement is rare. In cases without pulmonary symptoms, diagnosis may be difficult. We report a rare case involving initial progression of CNS symptoms followed by a pulmonary abnormality.A 14-year-old girl suffered from high fever, ataxic gait and paraparesis. MRI revealed diffuse T2 high signals with multiple gadolinium enhancements in the cerebellum, brain stem and cerebral white matter. Her symptoms briefly improved after steroid therapy, but ataxia gradually progressed. Dyspnea due to pulmonary interstitial involvement appeared when she was 18 years old. Steroid therapy proved effective for respiratory symptoms. At 20 years old she suffered from disseminated intravascular coagulopathy (DIC) and hemophagocytic syndrome (HPS) with respiratory symptoms and repeated seizures. Her symptoms improved after the administration of cyclophosphamide. Mild hemiparesis and gait disturbance appeared when she was 22 years old. MRI revealed new lesions at the basal ganglia and subcortical white matter, brain atrophy and diffuse T2 high intensity of cerebral white matter. Cyclophosphamide was effective and there has been no recurrence of symptoms in the last 5 years. We reviewed the non-tumorous LYG/AIL involving the CNS, and discussed the clinical features, MRI imaging and diagnosis of the LYG/AIL.