Melanoma and Sarcoidosis in Patients Receiving or Not Antineoplastic Therapy

Sarcoidosis and sarcoid-like reactions have been associated with many solid tumors including malignant melanoma. There are reports of melanoma patients who develop sarcoidosis without having received any antineoplastic treatment, but there are also melanoma patients who have received immunotherapy or targeted therapy and, therefore, develop drug-associated sarcoidosis. Herein, we describe 2 cases of thoracic sarcoidosis which occurred in asymptomatic patients with known malignant melanoma. The first patient had metastatic disease, and she was under melanoma treatment with BRAF/MEK inhibitors at the time of sarcoidosis diagnosis. The second case involves a patient with early stage melanoma who had received no antineoplastic treatment. In both cases, the thoracic lesions were suspicious for metastatic involvement, and it was the biopsy which gave the diagnosis of granulomatous disease. Sarcoidosis induced by immune checkpoint or BRAF/MEK inhibitors seems to be more frequent in real-world studies than in large phase 3 melanoma trials. Sarcoidosis can mimic metastasis, predominately in mediastinum, representing a diagnostic pitfall. Therefore, biopsies must always be performed to exclude the metastatic spread before initiation of any antineoplastic treatment.