BackgroundAlong with the medical development, organ transplant patients increase dramatically. Since these transplant patients take immunosuppressants for a long term, their immune functions are in a suppressed state, prone to all kinds of opportunistic infections and cancer. However, it is rarely reported that the kidney transplant recipients (KTRs) have pulmonary tuberculosis and lung cancer simultaneously.Case presentationA 60-year-old male was admitted because of persistent lung shadow for 2 years without any obvious symptom 8 years after renal transplant. T-SPOT test was positive but other etiological examinations for Mycobacterium tuberculosis were negative. Chest CT scan revealed two pulmonary lesions in the right upper and lower lobe respectively. 18F-fluorodesoxyglucose positron-emission tomography (FDG-PET) CT found FDG intake increased in both pulmonary consolidation lesions. CT-guided percutaneous transthoracic needle biopsy revealed lung adenocarcinoma and tuberculosis. The video-assisted thoracoscopic surgery was operated to resect the malignancy lesions. The patient received specific anti-tuberculosis therapy and was discharged. At the follow-up of 6 months post drug withdrawal, the patient was recovered very well.ConclusionsWe for the first time reported co-existence of smear-negative pulmonary TB and lung adenocarcinoma in a KTR, which highlighted the clinical awareness of co-occurrence of TB and malignancy after renal transplant and emphasized the value of biopsy and 18F-FDG-PET in early diagnosis of TB and cancer.