We present a 60-year-old man with biopsy-proven metastatic squamous cell carcinoma of the right inguinal and external iliac lymph nodes with unknown primary. Hypermetabolic soft tissue masses were identified in bilateral subscapular regions on follow-up positron emission tomography (PET)-computed tomography (CT) after completion of chemoradiation. The right subscapular mass was biopsied under CT guidance, and histopathology showed it to be elastofibroma dorsi. Elastofibroma dorsi is a benign tumor with no malignant potential; due to its ill-defined appearance and tracer uptake on PET-CT, it can be misdiagnosed as soft tissue sarcoma. This report describes the typical location and imaging features of this incidental hypermetabolic mass.