Coexistence of primary adenocarcinoma of the lung and Tsukamurella infection: a case report and review of the literature.

INTRODUCTION: A major diagnostic challenge in the evaluation of a cavitary lung lesion is to distinguish between infectious and malignant etiologies. CASE PRESENTATION: We present the case of an elderly man presenting with fever, hemoptysis and a left upper lobe cavitary lesion. Serial sputum cultures grew Tsukamurella pulmonis, a rare pathogen associated with cavitary pneumonia in immunocompromised patients. However, despite clinical improvement with antibiotic therapy targeted to the organism, concomitant discovery of a papillary thyroid carcinoma led to a needle biopsy of the cavitary lesion, which showed evidence of primary lung adenocarcinoma. CONCLUSION: This is the first description of Tsukamurella infection in the setting of primary lung carcinoma. The report also illustrates the potential complex nature of cavitary lesions and emphasizes the need to consider the coexistence of malignant and infectious processes in all patients, especially those with risk factors for malignancy that fail to improve on antibiotic therapy.