The scar sign: a useful finding on FDG PET/CT to distinguish sarcoidosis from other causes of lymphadenopathy.
Scar involvement is a rare but characteristic cutaneous manifestation of sarcoidosis. The concurrent presence of FDG-avid lymphadenopathy and scar involvement (the "scar sign") is a useful finding on FDG PET/CT to suggest sarcoidosis, especially when biopsy specimens are difficult to obtain. A 46-year-old woman who presented with fever, cough, and weight loss was found to have mediastinal and hilar lymphadenopathy on chest radiography and CT scan. FDG PET/CT scan showed FDG-avid lower cervical, mediastinal, hilar, and inguinal lymphadenopathy. There was also increased FDG uptake along an old hysterectomy scar. Mediastinoscopy and nodal biopsy revealed noncaseating granulomas compatible with sarcoidosis.
Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore. suat_jin_lu@yahoo.com
Suat-Jin
SJ
Lu
Victor K
VK
Lee
Suat W
SW
Loo
D002921:Cicatrix / Q000150:complications* / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012507:Sarcoidosis / Q000150:complications* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
D019788:Fluorodeoxyglucose F18