円錐上部症候群で発症し骨髄生検により診断した血管内リンパ腫の1例

A Case of Intravascular Malignant Lymphomatosis Presenting with Epicornus Syndrome and Diagnosed by Bone Marrow Biopsy

はじめに

　血管内リンパ腫（intravascular malignant lymphomatosis：IVL）は小血管内腔にリンパ腫が増殖する特殊な悪性リンパ腫である。血管外への浸潤は少なく，リンパ節の腫大も伴わない。全身の臓器に腫瘍塞栓などによる虚血病変を起こし得るが，特に脳，脊髄，神経根に血管障害を起こすことが特徴で，急性発症の神経症候で初発することが多い^1）。今回われわれは，円錐上部症候群で発症したIVLの症例を経験した。脊髄症状で発症するIVLは下位腰髄・仙髄の病変をきたすことが多く，原因不明の脊髄症の鑑別として本症は重要な鑑別疾患と考えられ，ここに報告する。

Abstract

　A-46-yerar-old woman admitted to our hospital because of numbness of bilateral lower limbs and urinary incontinence.　The initial neurological examination showed sensory impairment below S1 level with urinary incontinence, indicating epicornus syndrome.　Spinal MR imaging demonstrated unremarkable on conventional and enhanced images with Gd-DTPA.　Cerebrospinal fluid examination revealed slightly elevated protein level without pleocytosis.　Thereafter, subacute ascending myelopathy including flaccid paraparesis and urinary retention, developed.　Because the patient had low grade fever, fatigue, weight loss and elevated serum soluble IL-2 receptor and LDH titers, we investigated her for lymphoma.　Although lymphadenopathy or mass lesions were not found on whole-body CT scan, bone marrow biopsy showed the presence of inravascular large B-cell lymphoma (IVL).　Thus the patient's progressive myelopathy was probably caused by IVL invasion.　Ten days after the initiation of chemotherapy, her neurological symptoms transiently improved; however, her paraparesis and urinary incontinence gradually worsened thereafter, despite of treatment.　IVL often presents with neurological manifestations, including myelopathy.　There have been a few reports of IVL presenting with lower lumbar spinal cord and conus medullaris.　It should be noted that IVL can cause unidentified progressive ascending myelopathy without positive MRI findings.

(Received: July 30,2009,Accepted: October 13,2009)