Fluorodeoxyglucose PET/CT in subcutaneous sarcoidosis mimicking cutaneous lymphoma

Abstract

Sarcoidosis is a rare entity that may mimic lymphoma [1, 2] or tuberculosis, and, in the case of cutaneous lesions, melanoma [3]. [F]Fluorodeoxyglucose (FDG) positron emission tomography (PET) with computed tomography (CT) is often indicated in patients suffering from the so-called B symptoms and enlarged lymph nodes to assess the presence and stage of lymphoma. A 37-year-old woman with an enlarged lymph node in her neck and typical B symptoms such as fever, loss of weight and night sweats was referred for FDG PET/ CT. Multiple areas of increased uptake were seen subcutaneously in her arms, legs, neck, right cheek and lower back (figure). In addition, abnormal uptake was observed in lymph nodes in her neck, axillae and groins. Biopsy from a subcutaneous lesion and excision of a lymphoma in her neck were performed and histological examination of both revealed sarcoidosis instead of lymphoma. Cutaneous lesions are seen in 9–37% of cases of systemic sarcoidosis and can be classified into maculopapules, plaques, lupus pernio, scar sarcoidosis and subcutaneous sarcoidosis [4]. Although subcutaneous