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Imaging
features of primary central nervous system lymphoma at presentation
Case series from a regional cancer
centre
Rashmi Koul, MD, FRCPC; Tarek Dufan,
MD; Arbind Dubey, MD, FRCPC; Garry Schroeder, MD, FRCPC; Keith
Jones, MD, FRCR; Kalyani Vijay, MD; David D. Eisenstat, MD,
FRCPC
ABSTRACT
Rationale: Imaging
features in primary central nervous system lymphoma (PCNSL)
vary considerably. It is often challenging to distinguish
inflammatory or demyelinating white matter brain parenchymal
disorders from neoplastic processes based on radiologic findings.
This study’s purpose was to evaluate the imaging features
of PCNSL at presentation.
Methods and
materials: We evaluated pretreatment magnetic resonance
imaging (MRI) examinations of 43 patients diagnosed with PCNSL
in our institution.
Results:
Seventy lesions were found, with a mean diameter of 20 mm.
The most frequent locations of PCNSL were the periventricular
region in 18 patients (41.9%), followed by cerebral hemispheres
in 10 (23.2%). Four patients (9.3%) had a lesion in the corpus
callosum, 2 (4.6%) in basal ganglia bilaterally and 6 (13.9%)
had diffuse white matter involvement. A dural-based metastatic
lesion was evident in 1 patient (2.3%) and 2 (4.6%) had a
lesion originating from the wall of the third ventricle. One
patient presented with an epidural mass in the spinal canal
at the level of the second lumbar vertebra. Edema was seen
in 35 patients (81.4%), identified on T2-weighted images,
and a mass effect was evident in 5 (14.2%). The lesions were
hyperintense in 4 patients (9.3%) and hypointense in 9 (20.9%);
the remainder (69.8%) had heterogeneous signal intensity.
Conclusions:
PCNSL has a varied initial diagnostic imaging presentation
with periventricular location being most common. Radiologically,
PCNSL can mimic a variety of benign and malignant processes.
New diagnostic tools are required for differentiation, such
as single-photon emission computed tomography (SPECT), MR
spectroscopy, perfusion MRI and iron nanoparticle studies.
These tools can help in the differential diagnosis of neoplastic
phenomena with inflammatory conditions and should be further
investigated in clinical trials.
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