Subclinical granulomas in benign skin lesions heralding the onset of BRAF and MEK inhibitor–associated granulomatous dermatitis in a patient with metastatic melanoma

A 48 year-old white woman presented with melanoma, metastatic to the mediastinum. The primary lesion was ulcerated with a Breslow depth of 2.6 mm. The lesion was excised with appropriate margins. Right axillary sentinel lymph node biopsy was positive in 1 node, whereas a full lymph node dissection failed to find additional nodal involvement. She was treated with adjuvant interferon-β2, which was poorly tolerated and discontinued after 2 weeks. One year later, she presented with a 1-cm subcutaneous nodule above the excision scar, a biopsy of which confirmed metastatic melanoma.