Lymphoma is the fifth most common cancer in the United States, with an annual incidence of 74,490 estimated cases. Approximately 88% of these cancers are non-Hodgkin lymphomas (NHLs). The incidence of NHL has doubled over the last 20 years because of the increase in AIDS-related lymphoma and the use of immunosuppressive drugs with organ transplantation and cancer chemotherapy.
Several rare congenital immunodeficiency syndromes may result in CNS lymphoma, including Wiskott-Aldrich syndrome, X-linked immunodeficiency, immunoglobulin A deficiency, and severe immunodeficiency syndrome.
Primary lymphoma of the central nervous system is rare, representing about 1% of all lymphomas, less than 5% of all non-Hodgkin lymphoma, and 3-5% of brain tumors.
Magnetic resonance imaging (MRI) is the examination of choice for CNS lymphoma because of its high sensitivity and multiplanar capability.
MRI scans typically show a single or multiple poorly demarcated masses, more or less deeply located within the brain parenchyma. These masses demonstrate uniform intense gadolinium enhancement with little or no edema.
Although sensitive, MRI characteristics are not specific for CNS lymphoma; however, MRI findings may be suggestive of lymphoma in the proper clinical setting.
(See the image below.)
Nonenhanced CT scan of the head on a 56-year-old woman with a change in mental status shows a nodular, moderately hyperattenuating lesion adjacent to the right lateral ventricle, within the head of the caudate nucleus.
Approximately 10-30% of patients with systemic lymphoma have secondary CNS involvement
; primary lymphomas represent approximately 70-90% of all CNS lymphomas. Secondary systemic and primary CNS lymphomas have similar imaging characteristics. Meningeal involvement occurs commonly in patients with secondary lymphoma; it occurs less frequently in patients with primary lymphoma. Of patients with primary lymphoma, 75-85% present with supratentorial tumor. As many as 50% of patients present with multiple tumor nodules.
Gadolinium-based contrast agents have been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). NSF/NFD has occurred in patients with moderate to end-stage renal disease after being given a gadolinium-based contrast agent to enhance MRI or MRA scans. NSF/NFD is a debilitating and sometimes fatal disease. Characteristics include red or dark patches on the skin; burning, itching, swelling, hardening, and tightening of the skin; yellow spots on the whites of the eyes; joint stiffness with trouble moving or straightening the arms, hands, legs, or feet; pain deep in the hip bones or ribs; and muscle weakness.