American Journal of Neuroradiology

Case of the Month

Section Editor: Nicholas Stence, MD
Children's Hospital Colorado, Aurora, CO

Submit a Case Previous Cases

April 2021

Next Case of the Month Coming May 4...

Diffuse Large B-Cell Lymphoma

Background:
- Primary central nervous system lymphoma (PCNSL) is a type of non-Hodgkin lymphoma seen in the central nervous system. It is a form of a rare extranodal lymphoma accounting for approximately 3% of all intracranial tumors. Diffuse large B-cell lymphoma (DLBCL) is a subtype of PCNSL and is diagnosed pathologically with tissue sampling.
- This type of lymphoma has a high incidence in those who are immunosuppressed, such as AIDS and transplant patients, but has also been noted to have had increased incidence in immunocompetent populations.
Clinical Presentation:
- Presenting symptoms are nonspecific neurologic symptoms such as headaches, dizziness, and tinnitus.
- As the disease progresses and tumor/edema involve the brain parenchyma, other neurologic symptoms such as seizure may develop.
- Patients also frequently present with dermatologic findings including palpable nodules of the scalp that may or may not show signs of ulceration.
Key Diagnostic Features:
- Noncontrast CT typically demonstrates a mass in the superficial soft tissues, and in cases of calvarial involvement, will show changes of the cranium including tumoral infiltration without an aggressive destructive appearance.
- MRI findings typically involve equal or high signal on T1 images and postgadolinium scans revealed heterogeneous or homogeneous marked enhancement of the involved areas of the scalp and dura.
- Varying levels of edema can also be appreciated on T2 images depending upon the level of parenchymal involvement.
- Dural involvement is also commonly seen. Leptomeningeal enhancement within sulci that are adjacent to the extracranial involvement is common. The dura mater itself may appear as a focal lump or plaquelike thickening in involved areas, which may also mirror the appearance of other dural-based lesions.
Differential Diagnoses
- Invasive meningioma would likely present with “dural tail” sign and would demonstrate similar avid contrast enhancement.
- Meningeal metastasis can also cause calvarial erosion and would be most commonly seen in the setting of prostate and breast primaries. Typically, multiple lesions are seen.
- Leptomeningeal disease can present similarly; however, expect to see more diffuse disease versus our case being relatively focal.
- Hemangiopericytoma can look similar as a lobulated extra-axial mass with dural attachment and skull erosion.
Treatment:
- DLBCL is more indolent and has a better prognosis than systemic lymphoma with CNS metastasis.
- Due to its overall rare incidence, there is no standard treatment established for intracranial involvement of DLBCL. Treatment regimens are often a combination of surgical resection and systemic chemotherapy (CHOP and rituximab are commonly used) +/- adjuvant radiation therapy.
- Review of the literature found that radiation therapy is often excluded to minimize neurotoxicity side effects, with increased use in cases of relapse.