Abstract
RATIONALE: Esophageal cancer is one of the deadliest cancers in the world, with high incidence and mortality rates ranking among the top ten in China. The efficacy of conventional treatments is limited and often accompanied by severe adverse reactions, which results in unsatisfactory outcomes. The mechanism of immune checkpoint inhibitors (ICIs) is to activate cytotoxic T cells to kill tumor cells expressing tumor antigens. The application of ICIs has profoundly changed the mode of cancer treatment. However, the use of ICIs also induces a series of adverse reactions similar to autoimmune reactions, called immune-related adverse events (irAEs). Some ICIs can cause manifestations similar to those in the development of sarcoidosis, which are called sarcoidosis-like reactions or granulomatosis. PATIENT CONCERNS: We report a 50-year-old Chinese male patient. DIAGNOSES: The patient had been diagnosed with advanced esophageal squamous cell carcinoma , and was confirmed to have pulmonary sarcoidosis-like reactions associated with sintilimab, a human programmed cell death protein 1 (PD-1) inhibitor. INTERVENTIONS: The patient was administered corticosteroid treatment. OUTCOMES: After receiving steroid treatment, the patient's systemic and pulmonary symptoms improved rapidly. To our knowledge, this is the first report of pulmonary sarcoidosis-like reaction in a patient with esophageal squamous cell carcinoma. The patient then continued to receive 1 year of follow-up antitumor treatment after the appearance of lung pulmonary sarcoidosis-like reactions. The prognosis was good and the patient's condition is currently stable. LESSONS: The diagnosis of ICI-induced sarcoidosis often requires comprehensive evaluation through clinical, pathological, and radiological assessment. A subset of patients with sarcoidosis-like reactions may not require treatment unless there is organ dysfunction or severe clinical symptoms, and these reactions generally respond well to treatment. The occurrence of sarcoidosis-like reactions after immunotherapy is positively correlated with the long-term prognosis of cancer patients. However, this hypothesis requires larger prospective studies for validation.