Intravascular large B-cell lymphoma diagnosed by FDG-PET/CT and endometrial biopsy.

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of non-Hodgkin's lymphoma characterized by a proliferation of tumor cells within the lumina of small to medium-sized vessels. Because there are few or no concomitant solid lesions, a diagnosis of IVLBCL usually cannot be established by CT or MR imaging. Herein, we describe a case of IVLBCL involving the uterus, in which (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) was useful for diagnosis. A 47-year-old woman was referred to our hospital because of fever and anemia. Laboratory examination demonstrated anemia and thrombocytopenia. Bone marrow aspiration and biopsy showed hemophagocytosis without involvement of lymphoma cells. Random skin biopsy did not demonstrate lymphoma involvement. FDG-PET/CT imaging showed FDG accumulation in the uterus. MR imaging demonstrated uterine leiomyoma only. Based on these findings, uterine endometrial biopsy was performed and histological diagnosis of IVLBCL involving the uterus was established. She received 6 courses of R-CHOP therapy and high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation. At present, she remains in complete remission after 33 months.