[Intravascular large B-cell lymphoma revealed by proteinuria: a case report]

We report the case of an intravascular large B-cell lymphoma in a 49-year-old woman, which was revealed by proteinuria. This type of lymphoma is very rare and corresponds to the proliferation of malignant lymphoid cells within the lumina of small vessels, resulting in ischemic lesions involving mainly brain and skin. Renal involvement is quite rare and remains asymptomatic, being discovered at autopsy. In this case, the renal biopsy demonstrated the presence of large malignant B cells in the glomerular lumina, associated with minimal glomerular damage. The mechanisms of the proteinuria occurring during intravascular lymphoma remain to elucidate.