CNS lymphomas can have a myriad of presentations and imaging findings. The purpose of this exhibit is to elaborate the typical and atypical findings, advanced imaging findings, post treatment changes and response assessment of these lesions and to identity the mimics of CNS lymphomas.

CNS lymphomas are hematopoietic tumors consisting of two subtypes: Primary and secondary. Primary CNS lymphomas (PCNSL) represents a rare but aggressive form of extra-nodal non-Hodgkin lymphoma preferentially affecting the brain parenchyma, spinal cord,leptomeninges, and eye(vitreoretinal space). Secondary CNS lymphomas predominantly affect the leptomeningesin 2/3rd of the patients and often involved cranial nerves, spinal nerves and spinal cord. Parenchymal involvement is seen in 1/3rd of the secondary CNS lymphomas. Majority (95%) of primary CNS lymphomas are Diffuse large B cell lymphoma type, all the other types...

Typical findings of CNS lymphoma: PCNSL have predominantly parenchymal involvement. It is a solitary, hypercellular tumor with disruption of blood brain barrier showing homogenous enhancement, poor neovascularity and predilection for periventricular or subcortical regions(figure 1). The imaging features of primary and secondary CNS lymphoma are illustrated in table 1. Key features- Characteristic deep depression on the surface of the enhancing tumor termed as “Notch sign”is not uncommon(figure 1).This pattern of enhancement suggestirregular growth pattern as well as pliable and infiltrative property of the tumor. Other...

Knowledge of various imaging features of CNS lymphoma, its mimics and post treatment changes is essential for accurate diagnosis and assessment of treatment response.

S. Kumar: Nothing to disclose A. Javalgi: Nothing to disclose M. Varghese: Nothing to disclose

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