Gastric mucinous adenocarcinoma presenting with chronic cough, bronchovascular bundle thickening, and multiple pulmonary nodules: a case report

Background: Chronic cough is a prevalent respiratory symptom, with etiologies spanning various systems. In the clinical setting, there may be an overlooking of the underlying gastrointestinal etiology in the context gastric cancer combined with pulmonary lymphangitic carcinomatosis presenting with chronic cough in the absence of gastrointestinal symptom. It may lead to missed diagnosis, posing a significant challenge to accurate diagnosis. Case presentation: A 52-year-old female patient was admitted to the hospital due to chronic cough lasting for five months. Chest CT revealed bronchial bundle thickening, interlobular septal thickening, and multiple small nodular opacities within the lungs. Gastroscopy indicated an ulcerative mass in the gastric body. Post-radical gastrectomy pathological examination revealed gastric mucinous adenocarcinoma, with approximately 20% exhibiting signet ring cell carcinoma. The diagnosis was gastric mucinous adenocarcinoma combined with pulmonary lymphangitic carcinomatosis. One month post-surgery, the patient commenced regular chemotherapy with the SOX regimen (Oxaliplatin 170mg d1+Tegafur-uracil 50mg,bid,d1-d14,q21d).The patient received 6 cycles of chemotherapy and experienced no recurrence through follow-up via gastroscopy. HRCT indicated an expansion in pulmonary lesions, but no extrapulmonary metastasis. However, one month after the discontinuation of intravenous chemotherapy, the patient was examined with multiple bone metastases in the sternum, scapulas, ribs, and thoracolumbar vertebral bodies, with expanded pulmonary lesions. Ultimately, the patient discontinued treatment due to respiratory distress. Conclusion: This study reports a case of gastric mucinous adenocarcinoma with pulmonary lymphangitic carcinomatosis presenting as chronic cough. Our case report highlights the importance of emphasizing chronic cough, encouraging a broader diagnostic approach, and actively seeking and confirming the existence of potential extrapulmonary diseases to prevent missed diagnoses and misdiagnoses.