Subcutaneous sarcoidosis (Darier–Roussy sarcoidosis) with extensive disease on positron emission tomography: A case report and review of the literature

Cutaneous manifestations of sarcoidosis are common, but subcutaneous nodules are rare, originally described in 1904 by Darier and Roussy and thought to represent isolated skin disease. We present a 61‐year‐old male who presented with 3 months of subcutaneous nodules on the forearms and knees. Biopsy confirmed sarcoidosis. An [F‐18] fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) showed confluent uptake in the skin of forearms and knees, along with thighs and buttocks, mediastinal, hilar and upper abdominal lymph nodes, and multiple bones. He was well and treated with hydroxychloroquine 400 mg/day. The nodules resolved and a repeat FDG PET/CT at 5 months showed a significant decrease in the uptake at all involved sites. Although a PET scan can demonstrate extensive disease in a patient presenting with subcutaneous nodules, the literature suggests prognosis is good and treatment should start simply with the least toxic approach, such as with hydroxychloroquine therapy.