びまん性大細胞型B細胞性リンパ腫経過中に末梢神経障害をきたし初期のPET-CTで集積なく診断に苦慮したneurolymphomatosisの1例

A Case of Neurolymphomatosis: Peripheral Neuropathy Induced by Diffuse Large B-cell Lymphoma without any Abnormal Accumulation Observed on Early Positron Emission Tomography-Computed Tomography

びまん性大細胞型B細胞性リンパ腫と診断された64歳女性に，8コースの化学療法終了後に複視と四肢のしびれが出現した。複視出現後7日目のFDG-PETでは異常集積はなく，完全寛解と判断された。その後，四肢のしびれと脱力が進行し，41日目のFDG-PETでは両側腕神経叢と坐骨神経に異常集積を認め，neurolymphomatosisが示唆された。

FDG-PETはneurolymphomatosisの高感度の検査法ではあるが，本症例のように初期には異常集積を認めないことがあり，その際は画像検査を繰り返すことが必要と考えた。

Abstract

A 64-year-old woman with diffuse large B-cell Lymphoma (DLBCL) complained of double vision and pain sensation in her limbs after eight cycles of chemotherapy. F-fluorodexyglucose-positron emission tomography (FDG-PET) 7 days after the onset of double vision showed no abnormal accumulation and confirmed remission of DLBCL according to the international criteria. However, she developed limb weakness and severe paresthesia. The second FDG-PET 41 days after onset showed increased uptake at the both the brachial and lumbar plexuses, suggesting neurolymphomatosis. Although FDG-PET appears to be a highly sensitive diagnostic method for neurolymphomatosis, it is sometimes difficult to detect neurolymphomatosis in early diagnose, such as with this case. Therefore, multiple examinations are necessary to determine neurolymphomatosis.

(Received June 2, 2014; Accepted August 20, 2014; Published February 1, 2015)