2026年 · 第106卷第32期

The patient, a 48-year-old female, was admitted to the Department of Respiratory and Critical Care Medicine of the Eighth Medical Center of the People's Liberation Army on October 31, 2025, due to "cough and difficulty breathing for more than a month". More than a month before admission, there was no obvious cause for cough, coughing up white foamy sputum, accompanied by dyspnea after activity and in the left lateral decubitus position, without fear of chills, fever, chest pain and hemoptysis. There was no special past medical history. The patient's mother died of pancreatic cancer. Physical examination revealed low breathing sounds in the left lung, and dry rales could be heard. On September 27, 2025, the chest CT results of other hospitals showed low-density shadow of the left bronchus and sputum plug? Left pleural effusion with partial atelectasis in the left lung? Enhanced CT scan of the chest showed space occupation in the left lung and multiple metastases in both lungs. On November 3, 2025, the PET-CT results of our hospital showed a huge soft tissue shadow in the lower lobe of the left lung and a bronchial section in the lower lobe of the left lung. Unevenly increased FDG metabolism was considered, indicating a malignant tumor in the left lung, with a high probability of lung cancer, accompanied by obstructive atelectasis in the lower lobe of the left lung. Multiple soft tissue nodules of varying sizes were observed in both lungs, accompanied by a mild increase in FDG metabolism, indicating multiple lung metastases (Figures 1 and 2 show that the middle of the cross line occupies the left bronchial tumor). On November 1, 2025, a fiberoptic bronchoscopy was performed, revealing a bronchial mass in the lower lobe of the left lung (Figure 3). Pathological results showed a mucoadenocarcinoma (neoplasm in the lower lobe of the left lung), papillary type, with local mucus lake formation (Figure 4, hematoxylin-eosin staining × 100). Immunohistochemistry results showed CK7 (partial+), Cytokeratin (+), Ki-67 (+,<10%), Napsin A (+), TTF-1 (+), P40 (-). Genetic testing promptsEGFRandAct1Mutation. The final diagnosis was stage IV mucinous adenocarcinoma of the left lung (T₄N₀M_1a）。 He has been treated with vometinib and his condition is currently stable. Lung mucinous adenocarcinoma accounts for 3% to 10% of lung adenocarcinomas, mostly located in the periphery of the lung, and typically presents as diffuse "pneumonia"-like infiltration or multifocal lesions. However, no case primarily originating in the main bronchus has been reported so far. This case suggests that there may be multiple clinical subtypes of lung mucoadenocarcinoma, and its pathological mechanism deserves further exploration.