Intravascular Large B-Cell Lymphoma Presenting With Decreased Brain Uptake On F-18-Fluorodeoxyglucose Positron Emission Tomography: A Case Report And Literature Review

Intravascular large B cell lymphoma (IVLBCL) is a rare disease characterized by proliferation of lymphoma cells in small vessels. Unlike typical lymphoma, this disease does not cause lymphadenopathy, instead presenting with a wide range of symptoms. It is thus difficult to diagnose such cases, often delaying treatment. F-18-Fluorodeoxyglucose positron emission tomography (PET) is useful for diagnosing IVLBCL. Herein, this study describes a IVLBCL case presenting with decreased brain uptake, i.e. a so-called superscan on PET. The patient was a 60-year-old man who had experienced fevers and lower limb edema for 1 month. A blood test at his first visit revealed pancytopenia. A PET scan was performed for detailed examination. Pathological uptakes were observed in the bone marrow, liver and spleen. However, there was little uptake in the brain. Although IVLBCL was suspected, random skin biopsies revealed no abnormalities. Therefore, a liver biopsy was performed, which confirmed IVLBCL. Six cycles of R-CHOP therapy (rituximab, cyclophosphamide, doxorubicin, and oncovin) have been administered, to date, resulting in resolution of the pancytopenia. He has remained alive without recurrence for 13 months since the diagnosis of IVLBCL. In conclusion, patients with IVLBCL, which is characterized by proliferation of lymphoma cells in small vessels, may present with PET superscan findings, which may indicate a missed opportunity to treat the disease. However, PET superscan findings may also reflect a refractory pathological condition.