周産期に発症した末梢性T細胞リンパ腫頭蓋内転移の1例

A Case of Metastatic Peripheral T-cell Lymphoma of the Central Nervous System During the Perinatal Period

Ⅰ．はじめに

　妊娠中に合併する悪性腫瘍の中で悪性リンパ腫（malignant lymphoma：ML）は，乳癌，悪性黒色腫，子宮頚癌に続く頻度である⁸⁾．その中でも非Hodgkinリンパ腫（non Hodgkin lymphoma：NHL）の頻度は低く，さらに頭蓋内病変での発症は極めて稀である⁴⁾．

　われわれは，分娩3日後に意識障害で発症し，1カ月を超える精査と診断的治療の末に，脳生検でようやく診断に至った非定型末梢性T細胞性リンパ腫（peripheral T-cell lymphoma not otherwise specified：PTCL-NOS）の1例を経験した．妊娠・周産期における頭蓋内悪性腫瘍の合併は稀と思われがちだが，実際には周産期脳卒中の発症率と同程度との報告がある⁷⁾．予後は極めて不良となることが多いため，早期診断，早期治療開始が求められる．常に念頭に置いておくべき疾患であり，ここに文献的考察を加えて報告する．

　The diagnosis of malignant tumors during pregnancy is not uncommon；the incidence is one per six thousand pregnancies. However, the diagnosis of malignant lymphoma—especially T-cell lymphoma—during pregnancy is extremely rare. Thus, the early detection and management of T-cell lymphoma necessitates difficult decision-making.

　A 30-year-old woman developed consciousness disturbance on postpartum day three. Because brain MRI showed multiple edematous lesions in both hemispheres, vasculitis or encephalitis was initially suspected, and diagnostic therapy was initiated with the administration of steroids. One month later, the patient suddenly developed a subarachnoid hemorrhage followed by acute hydrocephalus. Emergent ventricular drainage and lesion biopsy were simultaneously performed. Based on the findings, the patient was diagnosed with peripheral T-cell lymphoma not otherwise specified（PTCL-NOS). Laboratory findings indicated Epstein-Barr virus（EBV）infection. Moreover, the same diagnosis was supported by breast and bone marrow biopsies. Thus, the brain lesions were presumed to be metastatic in nature. The prognosis of PTCL-NOS is severely poor in pregnant women as diagnosis is delayed owing to limitations of radiological examinations and because symptoms can be confused with those of other diseases or hyperemesis gravidarum. Additionally, the alteration of immunotolerance in association with pregnancy and EBV infection might have influenced the aggressive features of this case. When a pregnant woman presents with neurological symptoms, malignant lymphoma should be considered when making a differential diagnosis.