Lymphoma, a great imitator in neurology

•We report three cases of lymphoma mimicking sarcoidosis, vasculitis and infection.•Lymphoma can have protean manifestations. Obtaining tissue is key to diagnosis.•Elevated serum ACE is poorly sensitive and insufficiently specific for sarcoidosis.•In the diagnosis of intravascular lymphoma, random skin biopsy can be considered.•Structural and metabolic imaging have complementary roles in lymphoma evaluation.