COVID–19肺炎と鑑別を要した造血器腫瘍に併発した急性呼吸不全の1例(A case of acute respiratory failure accompanied by a hematopoietic tumor differentiated from COVID–19 pneumonia)

• Published in: Nihon Kyūkyū Igakkai zasshi 2023-07, Vol.34 (7), p.274-279
• Main Authors: 光, 間﨑, 靖, 金子, 尚実, 釣木澤, 英樹, 屋代, 佑一, 栗原, 文, 佐々木, 季久雄, 葉
• Format: Article
• Language: English
• Subjects: corticosteroid; ground glass opacity; intravascular large B cell lymphoma; すりガラス影; ステロイド; 血管内大細胞型B細胞リンパ腫
• ISSN: 1883-3772; 1883-3772
• DOI: 10.1002/jja2.12821

要旨 　症例は55歳の男性，発熱と呼吸困難感を主訴に来院した。本邦では新型コロナウイルス感染症（coronavirus disease 2019: COVID–19）の市中感染が流行し始めた時期であった。来院時の胸部CTではCOVID–19を疑う両側のすりガラス影を呈したが，SARS–CoV–2 PCR検査は陰性であった。呼吸状態は増悪し，気管挿管・人工呼吸器管理とし，ステロイド投与を開始した。集中治療の結果，約2週間の経過を経て抜管することができた。経過中，SARS–CoV–2 PCR検査を計3回施行したがすべて陰性であった。抜管後から関節痛と紫斑が出現し，血球減少が進行，末梢血からは異型細胞が検出された。骨髄検査では，末梢血と同様の異型細胞が，皮膚生検では真皮中層を中心に血管内および血管周囲にCD79a陽性細胞が検出され血管内大細胞型B細胞リンパ腫（intravascular large B cell lymphoma: IVLBCL）と診断し，近医血液内科へ転院となった。IVLBCLを含めた造血器悪性腫瘍に随伴する急性呼吸不全とCOVID–19肺炎はCT所見でのすりガラス影が酷似することが示唆された。CT所見ですりガラス影を呈し，SARS–CoV–2 PCR検査陰性の場合は，造血器腫瘍も鑑別に挙げる必要がある。 ABSTRACT A 55–year–old man visited our hospital with a chief complaint of fever and dyspnea. At the time, the spread of coronavirus disease 2019 (COVID–19) as a community–acquired infection had begun in Japan. A chest CT examination showed bilateral ground glass opacity (GGO) reminiscent of COVID–19, but a PCR test for SARS–CoV–2 was negative. The patient was intubated and placed on a ventilator after his respiratory status worsened, and systemic corticosteroid therapy was initiated. After about 2 weeks of treatment, he was successfully extubated. During the course of treatment, SARS–CoV–2 PCR tests were performed three times, but all the tests were negative. After extubation, arthralgia and a skin rash appeared, hematopenia progressed, and atypical cells were detected in peripheral blood. The same atypical cells were identified in the bone marrow. Additionally, CD79a– and CD20–positive cells were identified in and around the vessels of the skin and the bone marrow. He was transferred to the hematology unit with a diagnosis of intravascular large B–cell lymphoma (IVLBCL). Since the GGO caused by IVLBCL closely resemble those associated with COVID–19–related pneumonia, a means of differentiating “GGO” associated with COVID–19–related pneumonia and that associated with pneumonia accompanying a hematopoietic tumor is needed.