Intravascular lymphomatosis: a case presenting with encephalomyelitis and reactive haemophagocytic syndrome diagnosed by renal biopsy

Aims: To report an unusual instance of intravascular lymphomatosis presented with encephalomyelitis and reactive haemophagocytic syndrome, There was no skin involvement. The diagnosis was made on a renal biopsy, Methods ann results: The marrow smear was air dried and stained with Diff-Quik. The tissue sections were stained with haematoxylin and eosin, Masson trichrome, periodic acid-Schiff's reagent, Elastic van Gieson's stain, modified hexamine-silver technique and Maritius scarlet blue. Immunohistochemistry for CD45, CD20,CD45RO, Factor Vm related antigen, CD31 and CD34 was performed on paraffin-processed tissue, The marrow smear showed active haemophagocytosis in the histiocytes. The renal biopsy showed intravascular lymphomatosis with tumour cells positive for CD45 and CD20. Conclusion: The possibility of intravascular lymphomatosis should be considered in patients with reactive haemophagocytic syndrome where the underlying cause cannot be found after thorough investigation.