MR imaging of the brain in lymphomatoid granulomatosis

BACKGROUND AND PURPOSE: Clinical diagnosis of lymphomatoid granulomatosis (LG) of the brain, in patients without skin or chest lesions, usually is difficult because of the nonspecific neurologic manifestations, laboratory data, and CT appearance. Our aim was to characterize the MR appearance of LG of the brain. METHODS: We retrospectively reviewed the MR images in four patients (35 to 72 years old) with histologically confirmed LG of the brain. RESULTS: On T2-weighted images, we noted diffuse hyperintense lesions in the cerebral white matter bilaterally (n = 3), in the brain stem and cerebellar hemisphere (n = 1), and patchy hyperintense lesions the brain stem (n = 2). On contrast-enhanced T1-weighted images, we observed multiple punctate or linear enhancements residing along the perivascular space (n = 4), nodular enhancements (n = 2), ringlike enhancements (n = 1), and a large, enhanced mass (n = 1). All patients had multifocal lesions. CONCLUSION: Although the MR appearance of LG of the brain varies, multiple punctate or linear enhancements that reside along the perivascular space suggest LG.