Pulmonary tuberculosis mimicking cystic metastases: evolution from multiple cystic cavities to nodules during therapy

Pulmonary tuberculosis typically exhibits characteristic imaging findings; however, radiological manifestations can be atypical in certain cases, leading to potential misdiagnosis based solely on CT imaging. We describe a 59-year-old man who developed a 4-month history of cough and a 2-week fever during postoperative radiotherapy following esophagectomy for esophageal cancer. CT scans revealed multiple, scattered cystic cavities in both lungs, characterized by regular shape and well-defined borders. Following anti-tuberculosis therapy, the pre-existing cystic cavities collapsed and evolved into nodular opacities, a change highly suggestive of cystic metastases given the patient's history of esophageal cancer. A biopsy confirmed granulomatous inflammation, and follow-up at eight months after the initiation of anti-tuberculosis therapy showed near-complete resolution of the lesions. Although cystic pulmonary tuberculosis is rarely reported, this case is notable for its distinct cystic characteristics. To our knowledge, this is the first case to systematically document the transformation of cystic lesions into nodules during anti-tuberculosis therapy-a finding that may raise suspicion for cystic metastases and highlights the diverse and atypical radiological manifestations of tuberculosis in immunocompromised hosts.