Introduction. Ewing sarcoma is rare in medical practice, and evaluating
positron emission tomography/computed tomography 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 positron emission tomography/computed tomography
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.