Case 272.

History A 92-year-old bedridden woman presented to the emergency department from an assisted living facility with fever, cough, and swelling over the right lateral hip. She had baseline dementia and frailty and had been bedridden for 4 years. She did not have any recent falls or history of trauma at the site of swelling. She had a history of diffuse large B-cell lymphoma that had been diagnosed and treated 7 years ago, and thoracoabdominal CT at last follow-up 3 years ago did not show any recurrence. Physical examination findings were unremarkable except for a painful hard and fixed mass measuring approximately 5 × 5 × 10 cm (in the transverse, anteroposterior, and craniocaudal directions, respectively) located at the right lateral superior thigh. The overlying skin was intact, without any color changes. Pertinent blood test results showed an increased white blood cell count of 13 000/μL (13 ×10/L) (normal range, 3700-11 000/μL [3.7-11 ×10/L]). The remaining hematologic and biochemical test results were normal. Abdominal and pelvic CT performed at presentation did not show any abnormal lymph nodes. Because chest radiography showed consolidation in addition to typical clinical picture, the patient was diagnosed with pneumonia and underwent antibiotic treatment for 3 weeks. US ( Fig 1 ) and Doppler US ( Fig 2 ) of the mass were performed. MRI was not performed because the patient had a pacemaker; instead, CT of the lower extremity was performed ( Fig 3a , 3b ). Figure 1: US image of the mass at the level of the greater trochanter. Figure 2: Doppler US image of the caudal portion of the mass. Figure 3a: Axial unenhanced CT image of the lesion at the level of the greater trochanter. Coronal unenhanced CT image of the mass at the level of the greater trochanter. Figure 3b: Axial unenhanced CT image of the lesion at the level of the greater trochanter. Coronal unenhanced CT image of the mass at the level of the greater trochanter.