A 53-year-old man presented to our hospital with a 4-month history of cough and polypnea for 2 months. He was a former smoker and consumed 30 cigarettes daily for 40 years, and no particular personal or family medical history was reported. Physical examination showed stable vital signs, including blood pressure of 126/86 mmHg, pulse rate of 92 beats/min, respiratory rate of 20/min, and temperature of 36.4  C. Weakened breathing sounds were detected in the right lung. Cytokeratin fragment (CYFRA) 21-1 was elevated to 4.62 ng/mL, while other laboratory parameters were unremarkable. Bacteriology of sputum was negative for tubercle bacilli. The chest CT at admission showed a 5.9cmx3.9cm-sized lobular mass in the right hilar region with an irregular margin. The contrast-enhanced CT demonstrated heterogeneous enhancement of the mass, without necrosis or cavity, but with a contiguous tracheobronchial stenosis in the right upper-middle lobe. Adenopathy in the right hilar and mediastinum region was observed. Lesions did not demonstrate any cavitary, fiber, strips, and calcified shadow changes (Figure 1). Besides, distant metastasis was not found by an enhanced head magnetic resonance imaging, an enhanced abdominal CT and a full-body bone scan.
The patient underwent the TBLB in the hilar region, which showed that the mucosa in the right main bronchus swelled, and the right upper bronchial linear narrowed. When the tracheoscopy passed through the right middle bronchus, the mass in the hilar region was seen to invading the carina tracheal tube and easily to bleed when touched. Pathologic results by the TBLB revealed the mass in the right hilar region as chronic inflammation with necrosis, and the DNA fragment of Mycobacterium tuberculosis (Mtb) was found in the specimen (Figure 2). Considering that the patient had no history of tuberculosis and the CT scan showed no features of obsolete tuberculosis, the patient was diagnosed with TB. However, the CT and the TBLB findings still indicated highly possibility of coexisting lung cancer. Thus, the patient received a CT-guided percutaneous lung biopsy at the periphery of the same mass (Figure 3). The pathology showed a poorly differentiated squamous cell carcinoma (Figure 2).
Thus, the final main diagnosis was squamous cell lung cancer (cT4N2M0, stage IIIB). The second diagnosis was pulmonary TB. The patient was then suggested to start anti-TB treatment and assess chemotherapy with a readmission after anti-TB therapy for more than two weeks. Meanwhile, genetic testing for lung cancer was also recommended to conduct for the further evaluation of possible targeted drug therapy. Unfortunately, the patient was discharged after diagnosed with lung squamous cell carcinoma in consideration of medical expenses and poor prognosis. No more data was collected, and the patient died 6 months later in the telephone return visit.
Chest CT on admission. The white arrow indicated the lobular mass with heterogeneous enhancement on mediastinal window in the right hilar region (B).