Primary pulmonary adenoid cystic carcinoma presenting with ground-glass opacity nodules coexisting with male breast adenoid cystic carcinoma: A case report.

Adenoid cystic carcinoma (ACC) of the lung is a rare subtype of lung cancer characterized by tumor cells forming cystic or glandular structures. It predominantly arises in segmental or larger bronchi, typically presenting as solid nodules or masses on imaging. Previous studies describe it as a slow-growing, low-grade malignancy associated with favorable prognosis and low metastatic potential. A 29-year-old male underwent surgical resection for breast nodules, pathologically confirmed as ACC of the breast. During hospitalization, chest CT revealed multiple bilateral ground glass nodules (GGN), with the largest measuring 22 × 16 mm. Clinical diagnosis suggested multiple primary lung cancer (cT1cN0M0). Video-assisted thoracoscopic wedge resections were performed, and pathology confirmed ACC of the lung, though the origin (primary vs. metastatic) remained controversial. Postoperatively, the patient received 4 cycles of chemotherapy (cyclophosphamide + epirubicin + cisplatin). Follow-up imaging demonstrated progression of residual pulmonary nodules. ACC of the lung represents a rare pathological variant of lung cancer with insufficiently characterized clinical behavior. Further research is imperative to refine diagnostic strategies and therapeutic approaches.