2023 年 1 巻 2 号 p. 119-122
Invasive mucinous adenocarcinoma (IMA) is a subtype of lung adenocarcinoma with a poor prognosis. Delays in diagnosis and treatment are problematic due to the nonspecific symptoms of cough and sputum and the difficulty of diagnosis by bronchoscopy forceps biopsy. Transbronchial cryobiopsy (TBCB) is a lung biopsy technique that endoscopically obtains large specimens with limited crush artifacts. A 61-year-old woman presented to our hospital with a productive cough. Chest computed tomography (CT) showed mixed ground-glass opacities and consolidation of the right lower lobe. A forceps biopsy was performed endoscopically on the right lower lobe. However, no malignant findings were observed on histological examination. Therefore, we suspected organizing pneumonia and treated the patient with steroids as a diagnostic treatment. However, she did not improve. Her productive cough worsened during steroid tapering, and CT showed increased consolidation. We concluded that rebiopsy and TBCB were needed. Histopathologic examination revealed alveolar replacement of tumor cells with mucus, confirming the diagnosis of IMA. IMA, which is difficult to diagnose using forceps biopsy, can be diagnosed using TBCB. Clinicians might want to consider using TBCB for biopsies of persistent alveolar shadows similar to those of IMA.
