Pulmonary reversed halo cycles and consolidations after immunotherapy: A case report.

Background: Immune checkpoint inhibitor-associated interstitial lung disease (ICI-ILD) and opportunistic pneumonias are the main pulmonary complications during immunotherapy for malignancies. The organizing pneumonia (OP) pattern is one of the common radiological manifestations of ICI-ILD, and OP is the most common cause of reversed halo cycles and consolidations. However, opportunistic pneumonias should be excluded.

Case Summary: In this report, we described a case of a 44-year-old man with esophageal cancer who showed multiple reversed-halo cycles and consolidations on chest computed tomography (CT) after he had a cold during immunotherapy. He was diagnosed with esophageal squamous-cell cancer (T2NIM0) after surgery. Then, he was successfully treated with 6 cycles of chemotherapy plus tislelizumab, one cycle of radiotherapy and 9 cycles of tislelizumab. Two months later, he complained of low-grade fever and cough with nonpurulent sputum after he had a cold. Community-acquired pneumonia was considered, but moxifloxacin was ineffective. Chest CT showed multiple reversed-halo cycles and consolidations. was identified with next-generation sequence analysis of bronchoalveolar lavage fluid (BALF). Two months later, he improved with standard anti-tuberculosis medications. Both the cycles and consolidations disappeared in the repeat CT after 6 mo of medications.

Conclusion: When chest CT shows reversed-halo cycles and consolidations in patients during anticancer immunotherapy, both ICI-ILD and infectious pneumonia should be considered. BALF microbiological analysis was helpful to differentiate them.