白血病加療中にリング状陰影を呈した肺ムコール症

Pulmonary Mucormycosis with Reversed Halo Sign on Computed Tomography of Patient with Leukemia

胸部CT上のリング状陰影（RHS）はさまざまな疾患で認められる．近年好中球減少を伴う免疫抑制患者において，RHSの出現は侵襲性肺真菌症（特に肺ムコール症）に特異的な所見とされている．本症はしばしば致命的となるため早急な治療介入が必要である．われわれは，白血病加療中に胸部CT上でRHSを呈した肺ムコール症の1切除例を経験したので報告する．

The patient was a male in his 60s, who had undergone bone marrow transplantation because of lymphoblastic leukemia. He suffered from chest pain two weeks after the transplantation. A chest computed tomography （CT） showed reversed halo sign （RHS） in the right upper lobe of the lung. A bronchoscopic lung biopsy revealed mycelia, and the patient was diagnosed with pulmonary mucormycosis. Although antifungal drugs were administered, no significant improvements were observed. A right upper lobectomy of the lung was successfully performed, and no postoperative complications occurred. Pathological examination found nodular lesions with extensive necrotic foci inside, and inflammatory granulation tissue and mucormycosis with hyphae （＋） were found through Grocott staining. RHS in leukemia patients with neutropenia is specific to pulmonary mucormycosis. Pulmonary mucormycosis is a life-threatening disease, and urgent treatment intervention including surgical treatment is advisable.