Lymphomatoid granulomatosis: abnormalities of the brain at MR imaging

To retrospectively evaluate the magnetic resonance (MR) imaging features of lymphomatoid granulomatosis in the brain.

The study, including retrospective analysis of data, was approved by the institutional review board of the National Cancer Institute and complied with Health Insurance Portability and Accountability Act. All patients gave written informed consent. Thirty-one patients with pathologically confirmed lymphomatoid granulomatosis were enrolled in a natural history and treatment study at the National Institutes of Health. Twenty-five patients (median age, 50 years; range, 18-62 years; 18 men, seven women) were evaluated with MR imaging of the brain at study entry for the presence of brain lesions and enhancing characteristics. Patients with abnormal findings were reexamined at intervals ranging from 2 to 19 months, as medically indicated. Cytologic analysis and flow cytometry of cerebrospinal fluid (CSF) were performed. Statistical analysis was performed to compare neurologic and CSF findings in patients with brain MR imaging abnormalities and in patients without abnormalities. The sensitivity of brain MR imaging was compared with that of CSF studies.

Thirteen (52%) of 25 patients evaluated with MR imaging had a variety of brain abnormalities. Multiple focal intraparenchymal lesions, which exhibited T2 prolongation and commonly punctate or linear enhancement, were the most frequent abnormalities, and they were encountered in seven patients. The second most common finding was involvement of leptomeninges and cranial nerves, which manifested as abnormal enhancement on MR images obtained after contrast agent administration. This abnormality was seen in six patients. Involvement of dura mater was noted in another. Four patients had brain masses. Two had abnormal engorgement and intense enhancement of the choroid plexus. Most lesions resolved after treatment, but seven resulted in lacunar infarctions. Abnormal B cells were detected in the CSF with either cytologic techniques or flow cytometry in five patients.

Lymphomatoid granulomatosis has a high rate of central nervous system involvement and a variable spectrum of lesions at MR imaging. Findings in this study suggest that MR imaging is more sensitive than CSF cytologic analysis or flow cytometry for detection of central nervous system involvement from lymphomatoid granulomatosis.