case_images: PMC8034791_01
case_images: Magnetic resonance imaging of the left knee (presurgery) showing a large, lobulated, soft-tissue mass in the posterior aspect of the knee joint extending into the calf. The mass is inseparable from the medial head of gastrocnemius and popliteus muscle and is heterogeneously hyperintense on T2-weighted images. Popliteal vessels are displaced and are encased
case_images: WJNM-20-121-g001.jpg
case_images: PMC8034791_01_WJNM-20-121-g001.jpg
case_images: F1
case_images: MRI of the left knee joint was done, which showed a lobulated mass in the posterior aspect of the left knee joint extending into the calf [Figure 1].
case_images: Magnetic resonance imaging of the left knee (postsurgery) showing a recurrent mass with heterogeneously hyperintense on T2-weighted images in the posterior aspect of the knee joint encasing popliteal vessels
case_images: WJNM-20-121-g002.jpg
case_images: PMC8034791_01_WJNM-20-121-g002.jpg
case_images: F2
case_images: MRI of the left knee was done, which showed a soft-tissue mass in the popliteal fossa with intra-articular extension and encasing neurovascular bundles and was suggestive of disease recurrence [Figure 2].
case_images: Maximum intensity projection in the anterior and posterior views showing physiological tracer uptake in the brown fat, thymus, breasts, heart, liver, spleen, kidneys, and bladder. Increased abnormal tracer uptake is seen posterior to the left knee joint
case_images: WJNM-20-121-g003.jpg
case_images: PMC8034791_01_WJNM-20-121-g003.jpg
case_images: F3
case_images: No other focus of metabolically active disease was seen elsewhere [Figures 3-4].
case_images: Coronal positron emission tomography-computed tomographyfused images showing mildly fluorodeoxyglucose-avid soft-tissue mass (white arrow) in the left popliteal fossa involving popliteus and gastrocnemius muscles
case_images: WJNM-20-121-g004.jpg
case_images: PMC8034791_01_WJNM-20-121-g004.jpg
case_images: F4
case_images: No other focus of metabolically active disease was seen elsewhere [Figures 3-4].