Rapid pulmonary cavity formation caused by Mycobacterium avium complex in a chemotherapy patient.

A 71-year-old woman with recurrent ovarian cancer, who had previously undergone bilateral salpingo-oophorectomy, visited our hospital after experiencing inspiratory left chest pain and a productive cough for 10 days. She had already received five courses of chemotherapy (270 mg/m2 paclitaxel plus 550 mg/m2 carboplatin at 3-week intervals), and received her final course two weeks earlier.

On admission, her blood pressure was 110/74 mmHg, her heart rate was 87 beats/minute, her respiration rate was 16 breaths/minute, and her oxygen saturation on breathing room air was 98%. On auscultation, the patient’s chest sounded clear bilaterally. Her blood test results showed slight elevation of inflammatory markers. While no lesions were detected using positron emission tomography/computed tomography (PET/CT) one month earlier (Fig. 1a), a repeat chest CT scan revealed a pulmonary cavity lesion in the upper anterior segment of the left upper lobe. The lesion had a diameter of 20 mm (Fig. 1b) and consolidation was observed in the inferior lingular segment of the left lung. The patient was isolated, because her acute clinical course was indicative of tuberculosis, and an acid-fast staining test of the patient’s sputum revealed a positive result. A few days later, polymerase chain reaction (PCR) for Mycobacterium avium was positive, and PCR for Mycobacterium tuberculosis was negative. Mycobacterium cultures were subsequently positive for the Mycobacterium avium complex (MAC).

Fig. 1

(a) No cavity lesion observed in the upper anterior segment of the left upper lobe. (b) A cavity lesion with a diameter of 20 cm was observed in the upper anterior segment of the left upper lobe.

The acute emergence of a pulmonary cavity lesion caused by MAC is atypical, because in general these are develop gradually from nodular lesions [1]. Host defense mechanisms triggered during chemotherapy may have made it possible in this patient. The incidence of mycobacteriosis among cancer patients is approximately three times higher than in the general population [2], because of impairment of host defense mechanisms or immunosuppression due to chemotherapy [3]. There are few case reports that describe pulmonary cavity lesions in the upper lobe after administration of immunosuppressant agents [4]. Nontuberculous mycobacterium infections, including MAC, are now increasing among populations globally [5]. Although acute cavity formation is not a typical response to MAC lung infection, we should consider it as a possibility of in immunosuppressed patients.

Patient consent has been obtained by a document.

Conflict of interest

None of the authors has any financial interest to disclose or conflict of interest to declare.