Introduction: Sarcoidosis is a systemic idiopathic granulomatous disease, with thoracic involvement in approximately 90% of cases. The skin is the second most commonly affected organ. Non-systemic sarcoid-like reactions have been described in oncology patients, secondary to the malignancy itself or related to immunotherapy, often presenting with an asymptomatic or mildly symptomatic profile.

Clinical Case Description: We report three male patients with cutaneous biopsies suggestive of immunotherapy-induced sarcoidosis, referred from the Dermatologic Oncology, where they were being followed for melanoma with local and/or distant metastases. The median age was 62 years (range 56–67 years). Two patients were former smokers, the other a non-smoker. Regarding immunotherapy, two patients were receiving first-line treatment with pembrolizumab, and the other was on second-line treatment with nivolumab. The mean time from beginning of treatment until the diagnosis of cutaneous sarcoidosis was 4 months. Two patients underwent bronchoscopy, and bronchoalveolar lavage revealed a lymphocytic predominance (70 and 71%). Pulmonary function testing, performed in only one case, was within normal limits, including diffusing capacity for carbon monoxide (DLCO). With respect to imaging, none of the patients underwent high-resolution CT. All patients had 18F-FDG PET/CT scans demonstrating lymph node involvement, and two exhibited a micronodular pattern. Besides cutaneous and thoracic involvement, one patient had ophthalmologic involvement. One patient received systemic corticosteroid therapy, with limited improvement. Due to dyspnea, one patient was treated with inhaled corticosteroids combined with a long-acting beta-agonist (ICS/LABA). At the time of submission, one patient has died, 5 months after the diagnosis of immune-mediated sarcoidosis, due to oncological disease progression.

Conclusions: From the review conducted, immunotherapy-induced sarcoidosis occurs more frequently with monotherapy (pembrolizumab, ipilimumab, and nivolumab) or with the combination of ipilimumab and nivolumab. Any manifestation compatible with sarcoidosis, regardless of the system involved, in a cancer patient undergoing immunotherapy, should prompt thorough evaluation considering the possibility of a sarcoid-like reaction.