Learning objectives
1.
to review typical as well as atypical CT and MRI findings of PCNLS
2.
to illustrate the spectrum of appearances of PCNLS with selected case examples from our institution.
3.
to emphasize role of spectroscopy in differential considerations
4.
to briefly review the current literature.
Background
Primary central nervous system lymphoma (PCNSL) is a form of extranodal lymphoma defined as isolated involvement of the craniospinal axis in the absence of primary tumor elsewhere in the body.
PCNSLS aretypically involving the brain,
less often the leptomeninges,
eyes and spinal cord.
These rare aggressive neoplasms of the brain represent about 3 percent of all primary brain tumors [1]; their incidence is significantly higher in the immunocompromised patients then in general population.
Long-term immunosuppression in transplant patients,
AIDS and autoimmune disease are conditions associated...
Findings and procedure details
Our series consists of 70 patients admitted to our center for advanced MR exam whose findings included lymphoma in the differential diagnosis; In all patients,
patochistological examination of leasion was done and only by 11 was PCNLS confirmed .
10 patients underwent presurgical in vivo single-voxel MRS at short echo time (TE,
35 ms) and multi-voxel MR spectroscopic imaging at long TE (144 ms).
3.1.Pathohistology
PCNSLS are large B-cell non-Hodgkin lymphomas,
usually high or intermediate grade.
The brain is the only tissue environment in which...
Conclusion
Solitary,
homogeneously enhancing mass with predilection for the periventricular and superficial regions are features suggestive but not specific for PCNSL; also they may not always be present.
Atypical appearance is more frequent in immunocompromised patients and may be misleading.
DWI and spectroscopy have been shown to provide additional diagnostic information.
Spectroscopy may aid the differentiation between CNS neoplasm and nonneoplastic lesion such as toxoplasmosis/ PML in immunocompromised patients.
Proper characterization is mandatory in order to avoid misdiagnosis and an unnecessary extend of surgery.
References
1.
Baraniskin A,
,Deckert M,
Schulte-Altedorneburg G,
Schlegel U,
Schroers R.
Current strategies in the diagnosis of diffuse large B-cell lymphoma of the central nervous system.
Brit J Haematol.
2012 Feb; 56(4):421–32.
2.
Rubenstein J.L et al.
Gene expression and angiotropism in primary CNS lymphoma BLOOD 2006 May 107(9):3716-3723.
3.
Commins D.L.
Pathology of Primary Central Nervous System Lymphoma .
Neurosurg Focus.
2006 Nov;21(5):1-10
4.
Reiche W,
Hagen T,
Schuchardt V,
Billmann P.
Diffusion-weighted MR imaging improves diagnosis of CNS lymphomas.
Clinical Neurol and Neurosur....