Gallbladder Ewing's sarcoma with liver metastasis: a rare case report

Ewing's sarcoma (SE) / primitive neuroectodermal tumor (PNET) occurs most often in soft tissues of the extremities and in the paravertebral areas. As far as we know, there are only two other reports in the gallbladder SE / PNET literature, however, this is the first metastatic case in a 58-year-old man. Microscopically, small round cell neoplasms showed intense positive immunoreactive activity for CD99, as well as for neuron-specific enoase and synaphysophine.