[Intravascular lymphomatosis diagnosed by bone marrow biopsy]

Intravascular lymphomatosis (IVL) is a rare malignancy characterized by neoplastic proliferation of lymphoid cells within the lumina of small vessels. We report a case of IVL in a 69-year-old woman, who presented with pancytopenia and elevation of the serum LDH level. There was no skin eruption or neurological abnormalities. Clusters of abnormal lymphoid cells were barely evident in a peripheral blood smear. Laboratory examinations revealed high levels of LDH (2,602 IU/l) and sIL-2R (5,640 U/ml). Bone marrow aspiration revealed a normal cellular marrow with mild hemophagocytosis, but no tumor cells were detected. After admission, respiratory failure due to multiple pulmonary embolisms progressed, and continuous infusion of heparin had no apparent effect. Bone marrow vessels filled with lymphoma cells were observed in a biopsy specimen, thus establishing a diagnosis of IVL. Chemotherapy with the CHOP regimen was immediately instituted. The respiratory failure was dramatically improved, resulting in disappearance of the abnormal lymphoid cells from the bone marrow. After eight courses of CHOP, low-dose etoposide therapy was administered, and no symptoms of relapse were noticed. The diagnosis of IVL is difficult because it does not form masses of tumor cells. Bone marrow biopsy may be helpful for early diagnosis of IVL if the disease is suspected and searched for.