Primary Central Nervous System Lymphomatoid Granulomatosis Presenting as Diffuse Corpus Callosum Lesions.

Lymphomatoid granulomatosis (LYG) is a rare lymphoproliferative disease characterized by angiocentric and angiodestructive infiltrate. It primarily affects the lung and sometimes may also affect the central nervous system (CNS), skin, kidney, liver, etc., but the involvement of lymph nodes and/or bone marrow is extremely rare, and if present, other diagnoses are usually considered. Isolated CNS involvement is very rare, and its pathogenesis and biological behavior have been controversially discussed. Here, we report a 46-year-old man with diffuse and symmetrical corpus callosum involvement. The histopathological findings were in keeping with LYG. Since there was no evidence of involvement of other organs, he was diagnosed with primary CNS-LYG. He responded well to steroids and his symptoms improved significantly. We also conduct an English literature review to provide clues for the diagnosis and treatment of this disease.