粘膜内表層伸展を示した肺門部肺腺癌の1例

摘要

背景．喀痰細胞診での肺門部肺癌の発見例はほとhどは扁平上皮痰であり腺癌はまれである．我々の経験した粘膜内を表層伸展する肺門部肺腺癌の1例を報告する．症例．58歳の男性．咳嗽を主訴に近医を受診し喀痰細胞診でClass Ⅴと判定された．気管支鏡にて右上菓支B~1，B~2，B3分岐部に黄白色の粘膜褪色部位が見られ，同部位よりの生検で肺腺癌の診断を得た．胸部CTでは右上葉支から右主気管支にかけて気管支壁の肥厚が見られた．術前診断T1N0M0の肺門部早期肺腺癌の診断にて右肺管状上葉切除およびND2bのリンパ節郭清を施行した．術中病理診断にて右主気管支中枢側断端に癌の浸潤を認めたため，気管分岐部直下まで追加切除し中間気管支幹と端々吻合を行った．病理組織学上，末梢側はB~1，B~2，B~3の亜亜区域支まで，中枢側は気管分岐部直前および中下葉支入口部2軟骨輪前までの範囲にわたり，粘膜に沿った伸展が高度な肺門部肺腺癌と診断された．術後病期はT3N0M0，ⅡB期であった．吻合部への放射線治療を追加し術後6年で再発の兆候は認めていない．結論．粘膜内を表層伸展する極めてまれな肺門部腺癌の1例について報告した．Background. We encountered a case of adenocarcinoma of hilar type lung cancer detected by sputum cytology, with a unique tumor growth pattern. Case. A 58-year-old man complaining of a persistent cough had no tumor shadow on chest roentgenogram. However, sputum cytology revealed Class V malignant cells. Bronchoscopic findings showed faded white yellowish mucosa at the spur of the right B~1, B~2, B~3 segmental bronchi. A computed to mograph showed only thickenings of the bronchial walls from the right upper lobe bronchus to the main bronchus. Bronchial biopsy of the dull spur revealed adenocarcinoma. Right sleeve upper lobectomy and lymph node dissection were performed, and the right main bronchus was excised just below the carina due to spread of cancer. The lesion was pathologically diagnosed as a well-differentiated papillary adenocarcinoma, located at the hilar portion of the lung, which had spread mainly in the mucosa from just below the carina and within 2 rings from the bifurcation of middle and lower bronchus and to the subsegmental bronchi of B~1, B~2, B~3 peripherally. Postoperative irradiation was administered and the patient has been free from cancer for 6 years after surgery. Conclusion. We report a rare case of mucosal spreading hilar adenocarcinoma of the lung. More cases need to be analyzed to elucidate the pathophsyology of this type of lung cancer.