Sarcoidosis-like reactions in metastatic renal cell carcinoma patients treated with immune-based combinations

Aim: The incidence of drug-induced sarcoidosis-like reactions (DISR) in patients treated with immune checkpoint inhibitors (ICIs) is rising. We determine the incidence and characteristics of DISR in a metastatic renal cell carcinoma (mRCC) population. Methods: We retrospectively reviewed clinico-radiological data of 83 mRCC patients treated at a single institution with immune-based combinations. Results: 15 patients received immune-doublet (ipilimumab-nivolumab), while 68 patients received other immune-based combinations. Two cases of DISR (2.4%) were evidenced, with enlargement of mediastinal lymph nodes that mimicked disease progression, thus requiring a biopsy which showed histological features of DISR. Conclusion: In our series of the incidence of DISR, radiological and clinical features, are in line with literature. DISR diagnosis is often only radiological, and its occurrence is possibly associated with a better outcome.The development of sarcoidosis-like lesions (DISR) is a rare event observed in cancer patients receiving immunotherapy. DISR occurrence represents a huge diagnostic issue, because its clinical and radiological features simulate disease progression. We present a series of 83 patients with kidney cancer receiving immunotherapy. During the therapy, two of these patients showed enlargement of chest lymph nodes that could be interpreted as disease progression. However, the microscopic analysis of these lymph nodes showed evidence of DISR. In conclusion, DISR should be adequately recognized to correctly manage patients who receive immunotherapy.The development of sarcoidosis-like lesions is a rare event in cancer patients receiving immunotherapy. The occurrence of DISR may mimic disease progression, and it represents a diagnostic issue, considering the growing number of resected RCC treated with adjuvant immunotherapy.