Intravascular large B cell lymphoma (IVLBCL) presents various neurological symptoms, and the prognosis frequently deteriorates with a delay in diagnosis. In addition, for the diagnosis of IVLBCL, invasive biopsies are generally performed in main organs, such as the brain. We report a case of IVLBCL in which an early diagnosis was enabled by skin biopsy. The patient in this case had cauda equine syndrome and had developed multiple brain infarctions. She received six cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone) treatment and is currently in complete remission. At the macroscopic level, her lesions resembled senile angioma, commonly observed in normal elderly persons. Eruptions of this type are not currently recognised as IVLBCL lesions and might easily be overlooked. In cases in which IVLBCL could be suspected, an active search and biopsy of skin lesions, including an eruption of this type, are useful for early diagnosis and treatment.