18F-fluorodeoxyglucose positron emission tomography/computed tomography in primary Ewing sarcoma of the lung

Introduction Ewing sarcoma is rare in medical practice, and evaluating positron emission tomography / computed tomography (PET/CT) imaging of soft tissue Ewing sarcoma is a challenge. Primary Ewing sarcoma of the lung is an infrequent diagnosis. Case outline A 22-year-old female patient was sent for PET/CT examination to the Center for Nuclear Medicine with Positron Emission Tomography, of the University Medical Center of Serbia, with a referral diagnosis of primary Ewing sarcoma of the right lung. In parallel to tumor visualization, the PET/CT imaging showed a radiological entity named "kissing sign," due to an enlarged beaver tail liver. Conclusion According to the concept of functional mimicry and tissue specificity of molecular markers, a better understanding of the molecular mechanisms of soft tissue Ewing sarcoma is the challenge. These observations can be the platform for further investigation of new therapeutic regimens.