Incessant pericarditis due to lung cancer and obstructive pneumonia.

[UNLABELLED] An 83-year-old man was admitted to our hospital with chest and back pain accompanied by a high fever. His electrocardiogram showed ST elevation in the inferior leads, and transthoracic echocardiography revealed a moderate amount of pericardial effusion. Contrast-enhanced computed tomography revealed lung cancer adjacent to the pericardial sac and obstructive pneumonia. Emergent cardiac catheterization was performed; however, no coronary artery occlusion was detected. Based on these findings, a diagnosis of acute pericarditis was made. The patient was treated with colchicine, ibuprofen, and antibiotics. By the third day of hospitalization, his fever, chest pain, pericardial effusion, and ST elevation had improved. However, on the sixth day, his chest pain recurred, ST elevation reappeared, and the pericardial effusion increased. These findings gradually improved with conservative management. Our final diagnosis was incessant pericarditis. As the patient and his family declined invasive treatment, he was discharged on the 28th day of hospitalization under a policy of best supportive care. Incessant pericarditis with rapid alternation between improvement and exacerbation within a short period is considered uncommon. In the present case, the fluctuations in pericarditis were thought to be associated with obstructive pneumonia and pericardial invasion by lung cancer.

[LEARNING OBJECTIVE] ✓Incessant pericarditis is rare, but some cases of acute pericarditis may follow an incessant inflammatory course.✓In addition to common viral infections, other causes of pericarditis such as obstructive pneumonia and lung cancer should also be considered and investigated.