Solitary Cavitary Pulmonary Metastasis from Hormone Receptor-Positive Breast Cancer: A Rare Radiologic Presentation: Cavitary Breast Metastasis

Background: Pulmonary metastases from breast carcinoma typically present as multiple solid nodules or diffuse lung involvement. Cavitary pulmonary metastases are uncommon, especially when appearing as a solitary lesion, and may closely resemble infectious or primary cavitary lung diseases. These atypical radiologic presentations pose significant diagnostic challenges and can delay appropriate treatment.Case Presentation: We report the case of a 49-year-old woman with a history of right breast invasive ductal carcinoma diagnosed approximately nine years earlier. Her tumor was estrogen receptor-positive, progesterone receptor-positive, and HER2-negative. Initial treatment included lumpectomy, chemoradiotherapy, and endocrine therapy with tamoxifen. She presented with a persistent cough, and chest CT revealed a solitary thick-walled cavitary lesion in the right lower lung lobe. Bronchoscopy showed no endobronchial abnormalities, and bronchoalveolar lavage was negative for both malignancy and infection. Due to ongoing suspicion, a CT-guided transthoracic biopsy was performed, confirming metastatic carcinoma consistent with breast primary. This case highlights a rare instance of solitary cavitary pulmonary metastasis occurring several years after the initial treatment.Conclusion: Solitary cavitary pulmonary metastasis from hormone receptor-positive breast carcinoma is an exceptionally rare phenomenon that can mimic infectious or primary lung malignancies. Persistent cavitary lung lesions in patients with a prior history of breast cancer warrant thorough evaluation and tissue diagnosis, even after extended disease-free periods.