EBUS-TBNAで診断された放線菌による後縦隔膿瘍の1例

A Case of Posterior Mediastinal Abscess Due to Actinomycosis Diagnosed by EBUS-TBNA

要旨　放線菌症は内科的に診断が困難なことも多く，しばしば腫瘍との鑑別が難しい．これまでに超音波気管支鏡下針生検(endobronchial ultrasound-guided transbronchial needle aspiration;EBUS-TBNA)を施行し診断し得た肺放線菌症の報告はあるが，調べた範囲では縦隔放線菌症を診断したという報告は存在しない．

　症例は22歳女性．某年8月下旬に後頸部痛が出現，9月下旬に近医を受診し胸部CTで後縦隔に占拠性病変を指摘された．後縦隔病変に対しEBUS-TBNAを施行し病理学的検査で放線菌症と診断した．ペニシリン系抗菌薬にて治療を行い治療経過は良好であった．

　われわれはEBUS-TBNAで診断された放線菌症の1例を経験した．一般に放線菌症は診断が困難とされるがEBUS-TBNAにより低侵襲で診断可能であった．

It is often difficult to clinically distinguish actinomycosis from malignancy. While cases of pulmonary actinomycosis diagnosed by using endobronchial ultrasound-guided transbronchial needle aspiration(EBUS-TBNA)have been previously reported, no case of mediastinal actinomycosis diagnosed by performing EBUS-TBNA has been found.

The patient was a 22-year-old woman who presented with posterior region of neck pain beginning in the August. About one month later, she visited a doctor. Chest CT showed the lesion at the posterior mediastinum. EBUS-TBNA was performed on this lesion, and actinomycosis was diagnosed by pathological examination. The patient was treated with penicillin and made good progress.

This case illustrates the role of EBUS-TBNA in the diagnosis of actinomycosis. Diagnosis of actinomycosis is difficult, but EBUS-TBNA could provide a minimally invasive option.