A 66-year-old Chinese man was admitted to the Tumor Center of the First Affiliated Hospital of Guangzhou University of Chinese Medicine on September 21, 2018, complaining of a cough and expectoration for 5 months and fever for 2 months. During the period of visiting the outer hospital, chest and upper abdomen computed tomography (CT) scans were performed on April 26, showing a lung mass in the left inferior lung (size of approximately 45 × 43 mm) with some lymph node metastasis (including bilateral peribronchial lymph nodes, PBLN). CT-guided percutaneous biopsy and two endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) procedures were carried out for the biopsy in April. The pathology was adenocarcinoma. However, the patient refused to receive regular anticancer therapy until August. On August 1 and August 22, two courses of chemotherapy (tegafur gimeracil oteracil potassium capsule and carboplatin) were conducted, although low fever began in July. The prophylactic antibiotic was administered though the white blood cell count (WBCC), procalcitonin (PCT) and C-reactive protein (CRP) levels were in the normal range, after which there was defervescence. Based on his properties of fever, he was clinically diagnosed with cancer-related fever. In mid-September, the third chemotherapy was delayed to a vague later date because of a high fever, high WBCC and CRP levels, and severe myelosuppression when a chest CT showed a cyst cavity with the gas-liquid level in the left lung. Therefore, the patient was diagnosed with lung abscess and subsequently accepted antibiotic therapy and percutaneous abscess drainage. However, there was obstructed drainage and no symptom relief. The patient visited our oncology centre for further treatment. Once admitted, the patient underwent re-examination by CT, revealing extensive hydropneumothorax, and was then diagnosed with pyothorax. Moreover, laboratory inspection including high WBCC, CRP, PCT and low albumin levels, indicating infection and malnutrition. We adjusted the depth of the catheter that had been put in by the previous hospital and conducted closed thoracic drainage, after which the patient underwent a chest X-ray. We empirically used intravenous moxifloxacin beginning on September 21. In addition, the blood culture results were negative. We ordered bacterial cultures four times for the draining pus, and each result was positive; the bacteria that grew included Eikenella corrodens and Streptococcus anginosus. There was no improvement in symptoms. Thus, on September 26, we added piperacillin-tazobactam with moxifloxacin to cover the pathogens. However, the response was not good until the bacterial susceptibility test was determined on September 28. According to the outcome, we changed piperacillin-tazobactam with cefoperazone sulbactam because the bacteria were resistant to penicillins. Concurrently, we began thoracic washing with povidone iodine and metronidazole sodium chloride solution heated to physical body temperature (for a total of 6 days, twice per day), and we encouraged him to blow up balloons to enhance the draining. Echocardiography was performed on September 28, and the results showed that heart structure and function were both normal; therefore, we ruled out endocardial infection. Subsequently, the patient became afebrile, and the draining solution became cleared and tailed off. On October 18, the WBCC and CRP levels were in the normal range, and then he was discharged after more than 4 weeks of parenteral antibiotic therapy and thoracic draining. Moreover, 7 days of oral moxifloxacin was prescribed as discharge medication. Nutrition support was run throughout the whole medication period. From a telephone follow-up in December, we were informed that the latest CT scan showed complete removal of the abscess and that he was undergoing further anti-tumour therapy.